Do not wrap in square brackets already wrapped IPv6 addresses v2

There was already a fix b7df3a2d29

But it was lost in a9f7a99388 (diff-7d2da5068938564117bd318316bdd1ad)

redisson/src/main/java/org/redisson/connection/SentinelConnectionManager.java

@@ -501,7 +501,7 @@ public class SentinelConnectionManager extends MasterSlaveConnectionManager {
         if (host.contains(":")){
             String pureHost = host.replaceAll("[\\[\\]]", "");
             host = applyNatMap(pureHost);
-            if (host.contains(":")) {
+            if (host.contains(":") && !host.startsWith("[")) {
                 host = "[" + host + "]";
             }
         } else {