warning "Failed creating shared configuration url for null."

[jukzi]

Also seen in for example https://bugs.eclipse.org/bugs/show_bug.cgi?id=578775
Happens when configProps.getProperty(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA) returns null.

Can we just do a null check instead of MalformedURLException and warning please?

Thread [pool-6-thread-6] (Suspended (breakpoint at line 349 in org.eclipse.equinox.internal.frameworkadmin.equinox.EquinoxFwConfigFileParser))	
	owns: java.lang.Class<T> (org.eclipse.equinox.internal.p2.touchpoint.eclipse.EclipseTouchpoint) (id=245)	
	org.eclipse.equinox.internal.frameworkadmin.equinox.EquinoxFwConfigFileParser.findSharedConfigIniFile(java.io.File, java.lang.String) line: 349	
	org.eclipse.equinox.internal.frameworkadmin.equinox.EquinoxFwConfigFileParser.rememberSharedConfigurationTimestamp(java.util.Properties, org.eclipse.equinox.internal.provisional.frameworkadmin.Manipulator, java.io.File) line: 597	
	org.eclipse.equinox.internal.frameworkadmin.equinox.EquinoxFwConfigFileParser.saveFwConfig(org.eclipse.equinox.frameworkadmin.BundleInfo[], org.eclipse.equinox.internal.provisional.frameworkadmin.Manipulator, boolean, boolean) line: 501	
	org.eclipse.equinox.internal.frameworkadmin.equinox.EquinoxManipulatorImpl.save(boolean) line: 458	
	org.eclipse.equinox.internal.p2.touchpoint.eclipse.LazyManipulator.save(boolean) line: 104	
	org.eclipse.equinox.internal.p2.touchpoint.eclipse.EclipseTouchpoint.saveManipulator(org.eclipse.equinox.p2.engine.IProfile) line: 65	
	org.eclipse.equinox.internal.p2.touchpoint.eclipse.EclipseTouchpoint.commit(org.eclipse.equinox.p2.engine.IProfile) line: 144	
	org.eclipse.equinox.internal.p2.engine.EngineSession.commit(org.eclipse.core.runtime.IProgressMonitor) line: 126	
	org.eclipse.equinox.internal.p2.engine.Engine.perform(org.eclipse.equinox.p2.engine.IProfile, org.eclipse.equinox.p2.engine.IPhaseSet, org.eclipse.equinox.internal.p2.engine.Operand[], org.eclipse.equinox.p2.engine.ProvisioningContext, org.eclipse.core.runtime.IProgressMonitor) line: 98	
	org.eclipse.equinox.internal.p2.engine.Engine.perform(org.eclipse.equinox.p2.engine.IProvisioningPlan, org.eclipse.equinox.p2.engine.IPhaseSet, org.eclipse.core.runtime.IProgressMonitor) line: 48	
	org.eclipse.equinox.internal.provisional.p2.director.PlanExecutionHelper.executePlan(org.eclipse.equinox.p2.engine.IProvisioningPlan, org.eclipse.equinox.p2.engine.IEngine, org.eclipse.equinox.p2.engine.IPhaseSet, org.eclipse.equinox.p2.engine.ProvisioningContext, org.eclipse.core.runtime.IProgressMonitor) line: 48	
	org.eclipse.equinox.internal.provisional.p2.director.PlanExecutionHelper.executePlan(org.eclipse.equinox.p2.engine.IProvisioningPlan, org.eclipse.equinox.p2.engine.IEngine, org.eclipse.equinox.p2.engine.ProvisioningContext, org.eclipse.core.runtime.IProgressMonitor) line: 28	
	org.eclipse.equinox.internal.p2.director.app.DirectorApplication.executePlan(org.eclipse.equinox.p2.engine.ProvisioningContext, org.eclipse.equinox.p2.engine.IProvisioningPlan) line: 788	
	org.eclipse.equinox.internal.p2.director.app.DirectorApplication.planAndExecute(org.eclipse.equinox.p2.engine.IProfile, org.eclipse.equinox.p2.engine.ProvisioningContext, org.eclipse.equinox.internal.p2.director.ProfileChangeRequest) line: 778	
	org.eclipse.equinox.internal.p2.director.app.DirectorApplication.performProvisioningActions() line: 759	
	org.eclipse.equinox.internal.p2.director.app.DirectorApplication.run(java.lang.String[]) line: 1082	
	org.eclipse.tea.library.build.tasks.p2.TaskRunProductExport.createProduct(java.lang.String, java.io.File, java.io.File, org.eclipse.tea.library.build.model.PlatformTriple, org.eclipse.equinox.internal.p2.director.app.ILog) line: 158	
	org.eclipse.tea.library.build.tasks.p2.TaskRunProductExport.run(org.eclipse.tea.core.services.TaskingLog, org.eclipse.tea.library.build.p2.UpdateSiteManager, org.eclipse.tea.library.build.jar.JarManager, org.eclipse.tea.library.build.model.WorkspaceBuild) line: 105	
	jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(java.lang.reflect.Method, java.lang.Object, java.lang.Object[]) line: not available [native method]	
	jdk.internal.reflect.NativeMethodAccessorImpl.invoke(java.lang.Object, java.lang.Object[]) line: 77	
	jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(java.lang.Object, java.lang.Object[]) line: 43	
	java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object...) line: 568	
	org.eclipse.e4.core.internal.di.MethodRequestor.execute() line: 58	
	org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(java.lang.Object, java.lang.Class<?>, java.lang.Class<? extends java.lang.annotation.Annotation>, java.lang.Object, org.eclipse.e4.core.di.suppliers.PrimaryObjectSupplier, org.eclipse.e4.core.di.suppliers.PrimaryObjectSupplier, boolean, boolean, boolean) line: 317	
	org.eclipse.e4.core.internal.di.InjectorImpl.invoke(java.lang.Object, java.lang.Class<? extends java.lang.annotation.Annotation>, org.eclipse.e4.core.di.suppliers.PrimaryObjectSupplier) line: 232	
	org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(java.lang.Object, java.lang.Class<? extends java.lang.annotation.Annotation>, org.eclipse.e4.core.contexts.IEclipseContext) line: 129	
	org.eclipse.tea.core.BackgroundTask.lambda$0(org.eclipse.e4.core.contexts.IEclipseContext) line: 50	
	org.eclipse.tea.core.BackgroundTask$$Lambda$1682.0x0000000801ebd4e0.run() line: not available	
	java.util.concurrent.Executors$RunnableAdapter<T>.call() line: 539	
	java.util.concurrent.FutureTask<V>.run() line: 264	
	java.util.concurrent.ThreadPoolExecutor.runWorker(java.util.concurrent.ThreadPoolExecutor$Worker) line: 1136	
	java.util.concurrent.ThreadPoolExecutor$Worker.run() line: 635	
	java.lang.Thread.run() line: 833