Only disconnect connections that were established by node-resque.

lib/connection.js

@@ -98,7 +98,10 @@ connection.prototype.connect = function(callback){
 
 connection.prototype.disconnect = function(){
   var self = this;
-  return self.redis.quit();
+  // Only disconnect if we established the redis connection on our own.
+  if (!self.options.redis) {
+    return self.redis.quit();
+  }
 }
 
 connection.prototype.key = function(){