Make sure to also clear the daemon history

This may be a good idea to avoid leaking private information.
While the client correctly clear its own data, the daemon still
had a copy. In the future, this feature will be removed, but it is
still true for now.

src/historymodel.cpp

@@ -528,6 +528,11 @@ void HistoryModel::clearAllBackends() const
          backend->clear();
       }
    }
+
+   //TODO Remove this
+   //Clear the daemon history backend as apparently the Gnome client wont
+   //Use its native backend anytime soon
+   DBus::ConfigurationManager::instance().clearHistory();
 }