Private commit emails were introduced in !22560, but some parts of
GitLab were not updated to take account of them. This commit adds
support in places that were missed.
The private commit email is automatically generated in the format:
id-username@noreply.HOSTNAME
GitLab instance admins are able to change the HOSTNAME portion,
that defaults to Gitlab's hostname, to whatever they prefer.
GitLab Bot
dineshpanda
Nick Thomas
Tiago Botelho