check: Add one-way argument

--one-way argument will check that all files on source matches the files on detination,
but not the other way. For example files present on destination but not on source will not
trigger an error.

Fixes: #1526
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f