StandardError can make the daemon memory killer busy

Summary

In !16900 (merged), the daemon memory killer start_working has code logic as:

      def start_working
... ...
        while enabled?
          begin
            restart_sidekiq unless rss_within_range?
            sleep(CHECK_INTERVAL_SECONDS)
          rescue => e
            log_exception(e, __method__)
          rescue Exception => e # rubocop:disable Lint/RescueException
            log_exception(e, __method__ )
            raise e
          end
        end
... ...
      end

In the case when restart_sidekiq unless rss_within_range? throw StandardError, it will log the error and immediately continue do next loop iteration, without sleep(CHECK_INTERVAL_SECONDS). If this happens, it may bloat log file too much, and also the deamon thread is busy, until the StandardError gone.

Suggested fix is to always sleep(CHECK_INTERVAL_SECONDS) in the main loop body. Just re-order it as:

        while enabled?
          begin
            sleep(CHECK_INTERVAL_SECONDS)
            restart_sidekiq unless rss_within_range?
          rescue => e
... ...