Use error_threshold_timeout when filtering observed errors

Author: izuzak

lib/redis_client/circuit_breaker.rb

@@ -79,7 +79,7 @@ def refresh_state
 
     def record_error
       now = RedisClient.now
-      expiry = now - @error_timeout
+      expiry = now - @error_threshold_timeout
       @lock.synchronize do
         if @state == :closed
           @errors.reject! { |t| t < expiry }