Refactor delete

In PR #17, it now checks if there are files to delete. I used a variable to hold the contents of the find. Wanting someone to refactor the script a bit so that when deleting files it also uses the variable.

I don't know Linux or sh, I've just been Googling stuff. I tried some ways of doing it but the limited knowledge I've gained isn't enough to solve the problem.

https://github.com/jmqm/vaultwarden_backup/blob/479d78b9e305edb1f4e086081bd6032d3c1f2f0b/script.sh#L32-L33