Jobs silently fail when lock_ttl is reached and until_and_while_executing strategy is used

[jeromepl]

Describe the bug
When using the :until_and_while_executing strategy, if the lock_ttl is reached, jobs fail without raising an error (but do trigger the unlock_failed reflection).

Expected behavior
If the client-side lock has expired, then I would still expect the job to be executed.
An expired lock should not prevent execution of the job.

Current behavior
What happens when a job's lock_ttl is reached is that the strategy tries to first unlock the client-side lock, but since it doesn't exist it prevents execution the job. locksmith.unlock returns false here:

sidekiq-unique-jobs/lib/sidekiq_unique_jobs/lock/until_and_while_executing.rb

Lines 41 to 47 in 63c003f

	if locksmith.unlock
	# ensure_relocked do
	runtime_lock.execute { return yield }
	# end
	else
	reflect(:unlock_failed, item)
	end