[5.4] Added check not to retry non-existing jobs for clarity

[lasselehtinen]

Currently if you try to requeue non-existing jobs with artisan queue:retry it shows the error message and the info that the job has been requeued.

[root@server www]$ php artisan queue:retry foobar
No failed job matches the given ID [foobar].
The failed job [foobar] has been pushed back onto the queue!

This pull request changes the logic so the job is not retried if the id does not even exist and only shows the proper error message.

vagrant@homestead:~/Code/foobar$ php artisan queue:retry foo bar 9561
No failed job matches the given ID [foo].
No failed job matches the given ID [bar].
The failed job [9561] has been pushed back onto the queue!