Sentinel: bind source address

Some deployments need traffic sent from a specific address.  This
change uses the same policy as Cluster where the first listed bindaddr
becomes the source address for outgoing Sentinel communication.

Fixes #1667

src/sentinel.c

@@ -1676,7 +1676,7 @@ void sentinelReconnectInstance(sentinelRedisInstance *ri) {
 
     /* Commands connection. */
     if (ri->cc == NULL) {
-        ri->cc = redisAsyncConnect(ri->addr->ip,ri->addr->port);
+        ri->cc = redisAsyncConnectBind(ri->addr->ip,ri->addr->port,REDIS_BIND_ADDR);
         if (ri->cc->err) {
             sentinelEvent(REDIS_DEBUG,"-cmd-link-reconnection",ri,"%@ #%s",
                 ri->cc->errstr);
@@ -1698,7 +1698,7 @@ void sentinelReconnectInstance(sentinelRedisInstance *ri) {
     }
     /* Pub / Sub */
     if ((ri->flags & (SRI_MASTER|SRI_SLAVE)) && ri->pc == NULL) {
-        ri->pc = redisAsyncConnect(ri->addr->ip,ri->addr->port);
+        ri->pc = redisAsyncConnectBind(ri->addr->ip,ri->addr->port,REDIS_BIND_ADDR);
         if (ri->pc->err) {
             sentinelEvent(REDIS_DEBUG,"-pubsub-link-reconnection",ri,"%@ #%s",
                 ri->pc->errstr);