Dolphin plugin: build with QStringBuilder

shell_integration/dolphin/ownclouddolphinactionplugin.cpp

@@ -54,7 +54,7 @@ public:
         auto act = new QAction(parentWidget);
         act->setText(helper->shareActionString());
         connect(act, &QAction::triggered, this, [localFile, helper] {
-            helper->sendCommand("SHARE:"+localFile.toUtf8()+"\n");
+            helper->sendCommand(QByteArray("SHARE:"+localFile.toUtf8()+"\n"));
         } );
         return { act };
     }

shell_integration/dolphin/ownclouddolphinoverlayplugin.cpp

@@ -48,7 +48,7 @@ public:
             return QStringList();
         const QByteArray localFile = url.toLocalFile().toUtf8();
 
-        helper->sendCommand("RETRIEVE_FILE_STATUS:" + localFile + "\n");
+        helper->sendCommand(QByteArray("RETRIEVE_FILE_STATUS:" + localFile + "\n"));
 
         StatusMap::iterator it = m_status.find(localFile);
         if (it != m_status.constEnd()) {