Validate checkForChanges return value

app/src/updaters/appupdater.cpp

@@ -39,10 +39,10 @@ void AppUpdater::doUpdateLookUp()
     QtConcurrent::run([=]() {
         appimage::update::Updater updater(appImagePath.toStdString());
 
-        bool updateAvailable; // this is an output parameter!!!
-        updater.checkForChanges(updateAvailable);
+        bool updateAvailable = false; // this is an output parameter!!!
+        bool succed = updater.checkForChanges(updateAvailable);
 
-        if (updateAvailable) {
+        if (succed && updateAvailable) {
             qDebug() << "Update available";
             emit this->updateAvailable();
         } else {