Revert "global extension action: show all extensions actions."

This reverts commit 691c3d38.

src/vs/workbench/parts/extensions/electron-browser/extensionsActions.ts

@@ -93,7 +93,7 @@ export class GlobalExtensionsAction extends Action {
 	}
 
 	public run(): Promise {
-		return this.quickOpenService.show('>extensions: ');
+		return this.quickOpenService.show('ext install ');
 	}
 
 	protected isEnabled(): boolean {