CMakePM: Disable CMake actions after clearing CMake configuration

This way the user will not have actions that will result in the
following error: "Error: could not load cache".

Change-Id: I4b4f2015e1215d4c12c6aefc03f4ee5b419016c3
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildsystem.cpp

@@ -1239,6 +1239,7 @@ void CMakeBuildSystem::clearCMakeCache()
         path.removeRecursively();
 
     emit configurationCleared();
+    emitParsingFinished(false);
 }
 
 void CMakeBuildSystem::combineScanAndParse(bool restoredFromBackup)