[BugFix] use default avatar for ghost user (fix 500 error) (#9536)
* remove since it is there for 3years
* fix 500 error for ghost avatar
* dont insert "-1" in any case to issue.poster_id
* fix lint
* Test: ghost avatar link
* fix test
* Revert "remove since it is there for 3years"
This reverts commit
fd9ad05159c84ba804b126d2a959963d82578b22.
* Revert "dont insert "-1" in any case to issue.poster_id"
This reverts commit
05469ab6d815a6cc6478a256018b9ed1a12749e0.
Co-authored-by: zeripath <art27@cantab.net>