Qt4Project: Update code models if a folder watch changes the file list.

Fixes: c861af529e

Change-Id: I7ed8afd52ab694d053788fac7f3e994898f2dd84
Reviewed-on: http://codereview.qt-project.org/4969
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/qt4projectmanager/qt4nodes.cpp

@@ -733,6 +733,7 @@ void Qt4PriFileNode::folderChanged(const QString &folder)
 
     contents.updateSubFolders(this, this);
     m_project->updateFileList();
+    m_project->updateCodeModels();
 
     // The files to be packaged are listed inside the symbian build system.
     // We need to regenerate that list by running qmake