Fix for a crash if the identify dialog is open, the project changed and a layer removed before the first identify click in the new project

git-svn-id: http://svn.osgeo.org/qgis/trunk@11394 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/app/qgsmaptoolidentify.cpp

@@ -529,6 +529,7 @@ void QgsMapToolIdentify::removeLayer( QString layerID )
           delete mRubberBand;
           mRubberBand = 0;
         }
+        mLayer = 0;
       }
     }
   }