When deleting a file from xbvr files that do not exist on disk cause an error but the file is not removed

[Mellified]

Deleting a file from the xbvr web interface will fail if the file does not exist. The file is not removed from the xbvr database in this case however. This makes it difficult for users to clean up stale files that were removed from outside xbvr.

Instead, xbvr should leave databases entries in place only if the error returned by the underlying OS/filesystem is something other than "file not found" or equivalent. If the error is "file not found" then xbvr should remove that entry in the database.

Example log:

level=info msg="Deleting file /adult_v1/Funscripts/Free/Give In Vol 2 - Videos - Hypnotube.funscript"
level=error msg="error deleting file: remove /adult_v1/Funscripts/Free/Give In Vol 2 - Videos - Hypnotube.funscript: no such file or directory"