Sentinel: use comma as separator to publish hello messages.

We use comma to play well with IPv6 addresses, but the implementation is
still able to parse the old messages separated by colons.

src/sentinel.c

@@ -1741,9 +1741,13 @@ void sentinelReceiveHelloMessages(redisAsyncContext *c, void *reply, void *privd
 
     {
         int numtokens, port, removed, canfailover;
+        /* Separator changed from ":" to "," in recent versions in order to
+         * play well with IPv6 addresses. For now we make sure to parse both
+         * correctly detecting if there is "," inside the string. */
+        char *sep = strchr(r->element[2]->str,',') ? "," : ":";
         char **token = sdssplitlen(r->element[2]->str,
                                    r->element[2]->len,
-                                   ":",1,&numtokens);
+                                   sep,1,&numtokens);
         sentinelRedisInstance *sentinel;
 
         if (numtokens == 4) {
@@ -1841,8 +1845,7 @@ void sentinelPingInstance(sentinelRedisInstance *ri) {
         if (anetSockName(ri->cc->c.fd,ip,sizeof(ip),NULL) != -1) {
             char myaddr[REDIS_IP_STR_LEN+128];
 
-            // FIXME: IPv6 will break this due to nested : characters -geoffgarside
-            snprintf(myaddr,sizeof(myaddr),"%s:%d:%s:%d",
+            snprintf(myaddr,sizeof(myaddr),"%s,%d,%s,%d",
                 ip, server.port, server.runid,
                 (ri->flags & SRI_CAN_FAILOVER) != 0);
             retval = redisAsyncCommand(ri->cc,