Catch SSLError too when adding a provider

Expands ManageIQ#314.
KubeException already covers the common "certificate verify failed" SSL
errors but not rarer ones like "does not match the server certificate".
This might be resolved in Kubeclient or RestClient one day
(ManageIQ/kubeclient#240) but it's blocked
on backward compatibility concerns so let's catch it here for now.

get_hostname_from_routes is best-effort, should never crash UI.
Any SSL error will probably fail both get_hostname_from_routes and the
main validation code; the error from validation will then be displayed
in a red flash.
https://bugzilla.redhat.com/show_bug.cgi?id=1436221

app/controllers/mixins/ems_common_angular.rb

@@ -475,7 +475,7 @@ def get_hostname_from_routes(ems, endpoint_hash, token)
       client = ems.class.raw_connect(endpoint.hostname, endpoint.port,
                                      :service => :openshift, :bearer => token, :ssl_options => ssl_options)
       client.get_route('hawkular-metrics', 'openshift-infra').try(:spec).try(:host)
-    rescue KubeException => e
+    rescue KubeException, OpenSSL::SSL::SSLError => e
       $log.warn("MIQ(#{controller_name}_controller-#{action_name}): get_hostname_from_routes error: #{e}")
       nil
     end