Cleanup wrong code (#6067)

Author: omichel

src/webots/control/WbController.cpp

@@ -321,9 +321,6 @@ void WbController::start() {
   }
   file.write("");
   file.close();
-
-  // FIXME: from Qt 6.4 onwards, QDir::mkdir can be used to set the permissions
-  QProcess::execute("sh", QStringList() << "-c" << QString("chmod -R 777 %1").arg(mIpcPath));
 #endif
   // recover from a crash, when the previous server instance has not been cleaned up
   bool success = QLocalServer::removeServer(serverName);