Fix missing parameter in SG filelist query. Patch from fedora a t rea…

…dy2think.

Thanks very much for recognizing and fixing this.  Fixes #9350.

mythtv/programs/mythbackend/playbacksock.cpp

@@ -242,7 +242,7 @@ QStringList PlaybackSock::GetSGFileList(QString &host, QString &groupname,
     strlist << host;
     strlist << groupname;
     strlist << directory;
-    QString::number(fileNamesOnly);
+    strlist << QString::number(fileNamesOnly);
 
     SendReceiveStringList(strlist);