proper cleaning of server connector mock

frontend-js/src/test/js/ServerConnector-mock.js

@@ -12,6 +12,7 @@ var ServerConnectorMock = OriginalServerConnector;
 
 ServerConnectorMock.init = function() {
   this._customMap = null;
+  ServerConnectorMock.selectedLayout = null;
   ServerConnectorMock.zoomLevel = 2;
   ServerConnectorMock.listeners = [];
   ServerConnectorMock._waitingForAliasLayoutData = 0;