Fix the QUERY_FREE_SPACE_SUMMARY message

Seems that the summary message was missed in the conversion to 64bit from 2*32.

Fixes #9810

Signed-off-by: Gavin Hurlbut <ghurlbut@mythtv.org>

mythtv/programs/mythbackend/mainserver.cpp

@@ -2697,9 +2697,7 @@ void MainServer::HandleQueryFreeSpaceSummary(PlaybackSock *pbs)
     BackendQueryDiskSpace(fullStrList, true, true);
 
     // The TotalKB and UsedKB are the last two numbers encoded in the list
-    unsigned int index = fullStrList.size() - 4;
-    strList << fullStrList[index++];
-    strList << fullStrList[index++];
+    unsigned int index = fullStrList.size() - 2;
     strList << fullStrList[index++];
     strList << fullStrList[index++];