use killall instead of pkill

app/src/updaters/appupdater.cpp

@@ -65,7 +65,7 @@ void AppUpdater::doUpdate()
 
 void AppUpdater::doRestart()
 {
-    QProcess::startDetached("pkill", {"pling-store"});
+    QProcess::startDetached("killall", {"pling-store"});
 
     if (updateHelper != nullptr) {
         std::string pathToNewFile;