do not capitalise merge commit title in case there are more than one commit

Summary

Creating a merge request takes either the commit title as title of the MR in case there is just one commit or the branch name in case there are more. If one prefixes the branch name with the issue number e.g. gitlab-runner#123-please-do-not-capitalise then it is necessary that gitlab-runner is not capitalised in order that gitlab can make the link.

Steps to reproduce

1. create two commits in branch gitlab-runner#123-test
2. create a merge request => Gitlab-runner#.. will be used as title

Example Project

https://gitlab.com/robstoll/test-move-multiple-issues/-/merge_requests/new?change_branches=true&merge_request%5Bsource_branch%5D=gitlab-runner%23123-do-not-capitalise&merge_request%5Bsource_project_id%5D=15559629&merge_request%5Btarget_branch%5D=test&merge_request%5Btarget_project_id%5D=15559629

Chose test as target branch => you see gitlab-runner#.. Chose master as target branch => you see Gitlab-runner#..

What is the current bug behavior?

branch name gets capitalised

What is the expected correct behavior?

should not capitalise branch (at least not in case word follows #