QtVersionManager: Detect changes in sbs/system root settings

Otherwise the Qt options dialog won't emit a signal if just those paths
are changed in the settings.

Reviewed-By: hunger

src/plugins/qt4projectmanager/qtversionmanager.cpp

@@ -527,6 +527,10 @@ bool QtVersionManager::equals(QtVersion *a, QtVersion *b)
         return false;
     if (a->m_displayName != b->displayName())
         return false;
+    if (a->m_sbsV2Directory != b->m_sbsV2Directory)
+        return false;
+    if (a->m_systemRoot != b->m_systemRoot)
+        return false;
     return true;
 }