Fix incorrect error logging in Stats indexer and OAuth2 (#12387) (#12422)

Fix incorrect error logging in Stats indexer and OAuth2 (#12387) (#12422)

* Fix incorrect logging in oauth2.go

Fix #11945

Signed-off-by: Andrew Thornton <art27@cantab.net>
* Handle ErrAlreadyInQueue in stats indexer

Fix #12380

Signed-off-by: Andrew Thornton <art27@cantab.net>
* Fixes type in error message of indexer

Add the missing character in the error message.

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lieven Hollevoet <hollie@lika.be>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lieven Hollevoet <hollie@lika.be>