Mattermost notifications pushover reference pointing to non-existing url - 404

Description

When user action is one of below:

• pushed new branch
• deleted branch
• push to branch

Gitlab sends wrong reference url which is pointing to non-existing gitlab url - 404 error.

Steps to reproduce

1. Use latest Gitlab at the time of writing v16.0.1
2. Enable 'Mattermost notifications' integration with 'Push' trigger enabled
3. Push changes
4. Wrong message appears on integration mattermost channel

Wrong behaviour

Filip Bednarski pushed to branch master of group / project (Compare changes)

• 'master' pointing out to: https://gitlab.mydomain.com/group/project/commits/master which results in 404
• 'Compare changes' pointing out to: https://gitlab.mydomain.com/group/project/compare/0af04acd8d3bc19e27e9b616c563cafcc6fd0d4d...ed524e769baef46b8c26bb61221afd8593c6e759 which results in 404

Expected behaviour

Filip Bednarski pushed to branch master of group / project (Compare changes)

• 'master' pointing out to: https://gitlab.mydomain.com/group/project/-/commits/master
• 'Compare changes' pointing out to: https://gitlab.mydomain.com/group/project/-/compare/0af04acd8d3bc19e27e9b616c563cafcc6fd0d4d...ed524e769baef46b8c26bb61221afd8593c6e759