Fix log level of :retry_stopped event

`subscribe_log_level` was not called for `:retry_stopped` event but for
`:enqueue_retry` event. So no log level was set for `:retry_stopped`
event, and the log level of `:enqueue_retry` event was altered from
`:info` to `:error`.

This commit fixes the log level of `:retry_stopped` event to `:error`
and restores the log level of `:enqueue_retry` event to `:info`.

activejob/lib/active_job/log_subscriber.rb

@@ -125,7 +125,7 @@ def retry_stopped(event)
         "Stopped retrying #{job.class} (Job ID: #{job.job_id}) due to a #{ex.class} (#{ex.message}), which reoccurred on #{job.executions} attempts."
       end
     end
-    subscribe_log_level :enqueue_retry, :error
+    subscribe_log_level :retry_stopped, :error
 
     def discard(event)
       job = event.payload[:job]