rgw: metadata sync info should be shown at master zone of slave zoneg…

…roup

When executing 'radosgw-admin sync status', the metadata sync info should be shown on the srceen at master zone of slave zonegroup.

Signed-off-by: Jing Wenjun <jingwenjun@cmss.chinamobile.com>

src/rgw/rgw_admin.cc

@@ -1975,7 +1975,7 @@ static void sync_status(Formatter *formatter)
 
   list<string> md_status;
 
-  if (zone.id == zonegroup.master_zone) {
+  if (zonegroup.is_master && zone.id == zonegroup.master_zone) {
     md_status.push_back("no sync (zone is master)");
   } else {
     get_md_sync_status(md_status);