How to install without changing an existing 'git' user

I want to install Gitlab on a server that already has a user ‘git’.

Simply using apt-get install gitlab-ee will change the home directory of the ‘git’ user to /var/opt/gitlab without any warning. This breaks my existing setup.

Is there a way to use a different username?

Also, should’t the installation procedure at least warn you and ask for confirmation before changing an existing user configuration?