* response 404 for diff/patch of a commit that not exist
fix#15217
Signed-off-by: a1012112796 <1012112796@qq.com>
* Update routers/repo/commit.go
Co-authored-by: silverwind <me@silverwind.io>
* use ctx.NotFound()
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: silverwind <me@silverwind.io>