Degraded vscode-languageclient in order to fix rename.

package.json

@@ -518,6 +518,6 @@
     "tree-kill": "1.1.0",
     "find-up": "2.1.0",
     "elegant-spinner": "1.0.1",
-    "vscode-languageclient": "3.0.4"
+    "vscode-languageclient": "2.6.3"
   }
 }

src/components/language_client/manager.ts

@@ -45,11 +45,11 @@ export class Manager {
 
         this.languageClient.onDidChangeState(event => {
             if (event.newState === State.Running) {
-                this.languageClient.onNotification('rustDocument/diagnosticsBegin', () => {
+                this.languageClient.onNotification({ method: 'rustDocument/diagnosticsBegin' }, () => {
                     this.statusBarItem.setText('Analysis started');
                 });
 
-                this.languageClient.onNotification('rustDocument/diagnosticsEnd', () => {
+                this.languageClient.onNotification({ method: 'rustDocument/diagnosticsEnd' }, () => {
                     this.statusBarItem.setText('Analysis finished');
                 });
             }