perf: reduce too much shuffle which was intended to prevent biased subscription (#247)

Author: supercaracal

lib/redis_client/cluster/pub_sub.rb

@@ -64,12 +64,12 @@ def close
       def next_event(timeout = nil)
         return if @state_list.empty?
 
+        @state_list.shuffle!
         max_duration = calc_max_duration(timeout)
         starting = obtain_current_time
         loop do
           break if max_duration > 0 && obtain_current_time - starting > max_duration
 
-          @state_list.shuffle!
           @state_list.each do |pubsub|
             message = pubsub.take_message(timeout)
             return message if message