Remove old qt version settings on upgrade.

Change-Id: I1544c4c241fced2015d2bdfb57a70ce828223786
Reviewed-on: http://codereview.qt.nokia.com/1080
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/qtsupport/qtversionmanager.cpp

@@ -428,8 +428,7 @@ bool QtVersionManager::legacyRestore()
 
     }
     s->endArray();
-    // TODO add removal of old settings
-    // s->remove(QtVersionsSectionName);
+    s->remove(QtVersionsSectionName);
     return true;
 }