Repository: redis/redis

Issue:
[BUG] redis-benchmark --cluster doesn't support ipv6
**Describe the bug**
Hi, I'm trying to run redis-benchmark with cluster option and getting this error:
```
redis-benchmark -h SHARD_URI -a PASSWORD  --cluster
Cluster has 6 master nodes:

Master 0: 0ba80fdb77300de637600ef6497da252dd1274e8 2a02:6
Could not connect to Redis at 2a02:6: Name or service not known
WARN: could not fetch node CONFIG 2a02:6
Master 1: c1a83816a940c8401fef4eb618b2f60e92831316 2a02:6
Could not connect to Redis at 2a02:6: Name or service not known
WARN: could not fetch node CONFIG 2a02:6
Master 2: 4666482d50faf41fef1765b4459688bc919c4efa 2a02:6
Could not connect to Redis at 2a02:6: Name or service not known
WARN: could not fetch node CONFIG 2a02:6
Master 3: 3ad940e830055faab65febbe5e1e7e796be42a81 2a02:6
Could not connect to Redis at 2a02:6: Name or service not known
WARN: could not fetch node CONFIG 2a02:6
Master 4: d00cc077bcaab64caf7104d1567354171099ba15 2a02:6
Could not connect to Redis at 2a02:6: Name or service not known
WARN: could not fetch node CONFIG 2a02:6
Master 5: 2e8968388b944dbdb6dc399920ed836b94c0ded4 2a02:6
Could not connect to Redis at 2a02:6: Name or service not known
WARN: could not fetch node CONFIG 2a02:6
```
**To reproduce**

Run `redis-benchmark -h SHARD_URI -a PASSWORD  --cluster` with a cluster where Redis hosts have ipv6-addresses only.

**Expected behavior**

redis-benchmark runs against all cluster shardes.

**Additional information**
```
$ redis-benchmark -v
redis-benchmark 6.2.6
```




Discussion:

Patch:
diff --git a/src/redis-benchmark.c b/src/redis-benchmark.c
index 64893ac37e5..9b183559d80 100644
--- a/src/redis-benchmark.c
+++ b/src/redis-benchmark.c
@@ -1118,6 +1118,9 @@ static clusterNode **addClusterNode(clusterNode *node) {
     return config.cluster_nodes;
 }
 
+/* TODO: This should be refactored to use CLUSTER SLOTS, the migrating/importing
+ * information is anyway not used.
+ */
 static int fetchClusterConfiguration() {
     int success = 1;
     redisContext *ctx = NULL;
@@ -1179,7 +1182,7 @@ static int fetchClusterConfiguration() {
         clusterNode *node = NULL;
         char *ip = NULL;
         int port = 0;
-        char *paddr = strchr(addr, ':');
+        char *paddr = strrchr(addr, ':');
         if (paddr != NULL) {
             *paddr = '\0';
             ip = addr;