we must always respect the output of sdscat, also change the string so its not a substring of other config params

Former-commit-id: e50313b20718bc8df0a53c11b0960e4bcb2177d4

src/server.cpp

@@ -4646,7 +4646,7 @@ sds genRedisInfoString(const char *section) {
                 fAllUp = fAllUp && mi->repl_state == REPL_STATE_CONNECTED;
             }
 
-            sdscatprintf(info, "all_master_link_status:%s\r\n",
+            info = sdscatprintf(info, "master_global_link_status:%s\r\n",
                 fAllUp ? "up" : "down");
 
             int cmasters = 0;