500 error when default banch doesn't exist on owner/repo/branches page #18265
Description
Gitea version: 1.15.9
Jan 13 05:25:12 my-host gitea[10979]: 2022/01/13 05:25:12 Started GET /testuser/pandas/branches for 127.0.0.1:48032
Jan 13 05:25:12 my-host gitea[10979]: 2022/01/13 05:25:12 ...s/web/repo/branch.go:168:loadBranches() [E] loadBranches: get default branch: branch does not exist [name: master]
Jan 13 05:25:12 my-host gitea[10979]: 2022/01/13 05:25:12 ...s/web/repo/branch.go:169:loadBranches() [E] GetDefaultBranch: branch does not exist [name: master]
Jan 13 05:25:12 my-host gitea[10979]: 2022/01/13 05:25:12 Completed GET /testuser/pandas/branches 500 Internal Server Error in 110.488967ms
Jan 13 05:25:12 my-host gitea[10979]: 2022/01/13 05:25:12 Started GET /assets/img/500.png for 127.0.0.1:48034