Force-push to base repo's ref/pull/#/head (#3393)
Force-push to base repo's ref/pull/#/head (#3393)

* Force-push to base repo's ref/pull/#/head

Fixes force-pushing to pull request branches, otherwise failing with:

[...gitea/models/pull.go:1022 AddTestPullRequestTask()] [E] PushToBaseRepo: Push: exit status 1 - To /path/to/gitea-repositories/org/repo.git
 ! [rejected]        issue-fix -> refs/pull/20/head (non-fast-forward)

* format

kubatyszko/gitea,lafriks/gitea,dnmgns/gitea,kubatyszko/gitea,typeless/gitea,kjellkvinge/gitea,lunny/gitea,sapk-fork/gitea,vdbt/gitea,tboerger/gitea,Bwko/gitea,typeless/gitea,dl5rcw/gitea,mjwwit/gitea,sapk-fork/gitea,kubatyszko/gitea,cez81/gitea,go-gitea/gitea,go-gitea/gitea,dnmgns/gitea,lunny/gitea,mjwwit/gitea,typeless/gitea,cez81/gitea,go-gitea/gitea,Bwko/gitea,vCaesar/gitea,tboerger/gitea,vCaesar/gitea,kjellkvinge/gitea,lafriks/gitea,lunny/gitea,sapk-fork/gitea,kjellkvinge/gitea,vdbt/gitea,dnmgns/gitea,Bwko/gitea,lafriks/gitea,sapk-fork/gitea,cez81/gitea,tboerger/gitea,typeless/gitea