The link to pull request on ui is wrong

Hello, I found a bug that the link to pull request for gh on ui is not right, Please have a look, Thanks.

view:

real: https://github.com/go-gitea/gitea/pull/16125
get: https://github.com/go-gitea/gitea/tree/undefined

link:
https://drone.gitea.io/go-gitea/gitea/43481/2/14