QbsProject: Remove unread attribute

Also remove the signal CppProjectUpdater::projectInfoUpdated() which is
now unused.

Change-Id: I65afe8f96cd8175edaf8ccb6e5067e4f9cd8d99f
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/cpptools/cppprojectupdater.h

@@ -49,9 +49,6 @@ public:
     void update(const ProjectUpdateInfo &projectUpdateInfo);
     void cancel();
 
-signals:
-    void projectInfoUpdated(const ProjectInfo &projectInfo);
-
 private:
     void cancelAndWaitForFinished();