(js) Disable autogrow plugin in CKEditor

Fixes #4239

UI/WebServerResources/ckeditor/config.js

@@ -26,9 +26,7 @@ CKEDITOR.editorConfig = function( config ) {
 
   // Configure autogrow
   // http://docs.ckeditor.com/#!/guide/dev_autogrow
-  config.autoGrow_onStartup = true;
-  config.autoGrow_minHeight = 300;
-  config.autoGrow_bottomSpace = 0;
+  config.removePlugins = 'autogrow';
 
   // Disables the built-in words spell checker if browser provides one. Defaults to true.
   // http://docs.ckeditor.com/#!/api/CKEDITOR.config-cfg-disableNativeSpellChecker