gitea: link to create PR after push is missing after update from 1.8 to 1.9 on existing repos

• Gitea version (or commit ref): 1.9.2
• Git version: 2.17.1
• Operating system: Ubuntu Bionic 18.04
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No
  • Not relevant
• Log gist:

This is the server side log when pushing a branch:

Aug 28 09:18:48 gitea gitea[12311]: 2019/08/28 09:18:48 modules/ssh/ssh.go:181:func1() [E] SearchPublicKeyByContent: public key does not exist [id: 0]
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Started GET /api/internal/serv/command/23/repo/test-testproject?mode=2&verb=git-receive-pack for 127.0.0.1
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Completed GET /api/internal/serv/command/23/repo/test-testproject?mode=2&verb=git-receive-pack 200 OK in 46.200043ms
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Started GET /api/internal/hook/pre-receive/repo/test-testproject?old=0000000000000000000000000000000000000000&new=e5d620284e950f7ac1fe361ab6a92ac01dd98d02&ref=refs%2Fheads%2Ffoo&userID=21&gitObjectDirectory=%2Fsrv%2Fgitea%2Frepositories%2Frepo%2Ftest-testproject.git%2F.%2Fobjects%2Fincoming-jai1uS&gitAlternativeObjectDirectories=%2Fsrv%2Fgitea%2Frepositories%2Frepo%2Ftest-testproject.git%2F.%2Fobjects&gitQuarantinePath=%2Fsrv%2Fgitea%2Frepositories%2Frepo%2Ftest-testproject.git%2F.%2Fobjects%2Fincoming-jai1uS&prID=0 for 127.0.0.1
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Completed GET /api/internal/hook/pre-receive/repo/test-testproject?old=0000000000000000000000000000000000000000&new=e5d620284e950f7ac1fe361ab6a92ac01dd98d02&ref=refs%2Fheads%2Ffoo&userID=21&gitObjectDirectory=%2Fsrv%2Fgitea%2Frepositories%2Frepo%2Ftest-testproject.git%2F.%2Fobjects%2Fincoming-jai1uS&gitAlternativeObjectDirectories=%2Fsrv%2Fgitea%2Frepositories%2Frepo%2Ftest-testproject.git%2F.%2Fobjects&gitQuarantinePath=%2Fsrv%2Fgitea%2Frepositories%2Frepo%2Ftest-testproject.git%2F.%2Fobjects%2Fincoming-jai1uS&prID=0 200 OK in 15.310619ms
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Started GET /api/internal/hook/post-receive/repo/test-testproject?old=0000000000000000000000000000000000000000&new=e5d620284e950f7ac1fe361ab6a92ac01dd98d02&ref=refs%2Fheads%2Ffoo&userID=21&username=repo for 127.0.0.1
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Completed GET /api/internal/hook/post-receive/repo/test-testproject?old=0000000000000000000000000000000000000000&new=e5d620284e950f7ac1fe361ab6a92ac01dd98d02&ref=refs%2Fheads%2Ffoo&userID=21&username=repo 200 OK in 166.081004ms
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Started POST /api/internal/ssh/23/update/60351 for 127.0.0.1
Aug 28 09:18:48 gitea gitea[12311]: [Macaron] 2019-08-28 09:18:48: Completed POST /api/internal/ssh/23/update/60351 200 OK in 21.996506ms

My local shell just gives:

git push --set-upstream origin foo
Total 0 (delta 0), reused 0 (delta 0)
To ssh://git.example.com:2222/repo/test-testproject.git
 * [new branch]      foo -> foo
Branch 'foo' set up to track remote branch 'foo' from 'origin'.

Description

Today i’ve managed to update Gitea from 1.8.2 to 1.9.2 and after pushing a new branch, i’m missing the remote message to create a new PR introduced in #4716