Make response for "connected" return null when activeMasterClient is still null. (As in on startup, if a client instantly checks connected, the activeMasterClient will still be null and not set yet from the sentinel query).

Author: Derek Bredensteiner

lib/sentinel.js

@@ -312,7 +312,11 @@ RedisSentinelClient.prototype.getMaster = function getMaster() {
   'stream' /* ?? */
   ].forEach(function(staticProp){
     RedisSentinelClient.prototype.__defineGetter__(staticProp, function(){
-      return this.activeMasterClient[staticProp];
+      if (this.activeMasterClient !== null) {
+        return this.activeMasterClient[staticProp]; 
+      } else {
+        return null;
+      }
     });
 
     // might as well have a setter too...?