mask whole window with waitMsgTarget

Else the buttons are still functional, and the user can trigger
additional command (i.e. several restore processes).

www/manager/Utils.js

@@ -360,7 +360,7 @@ Ext.define('PVE.Utils', { statics: {
 	var target = newopts.waitMsgTarget;
 	if (target) {
 	    // Note: ExtJS bug - this does not work when component is not rendered
-	    target.setLoading(newopts.waitMsg, true);
+	    target.setLoading(newopts.waitMsg);
 	}
 	Ext.Ajax.request(newopts);
     },

www/manager/window/Restore.js

@@ -58,6 +58,7 @@ Ext.define('PVE.window.Restore', {
 		url: url,
 		params: params,
 		method: 'POST',
+		waitMsgTarget: me,
 		failure: function (response, opts) {
 		    Ext.Msg.alert('Error', response.htmlStatus);
 		},