### Description When syncing users from ldap, if user doesn't have email field, username@localhost is used https://github.com/go-gitea/gitea/blob/v1.17.2/services/auth/source/ldap/source_sync.go#L88 Later when trying to edit this user from admin page, I'm getting an error that email is invalid ### Gitea Version 1.17.0 ### Can you reproduce the bug on the Gitea demo site? No ### Log Gist _No response_ ### Screenshots _No response_ ### Git Version _No response_ ### Operating System _No response_ ### How are you running Gitea? Downloaded binary from release page, run with systemd ### Database _No response_