Use of HTTP or HTTPS should be configurable for merge request creation

**Describe the bug**
One of my on-prem VCS systems (gitlab-type) mandates the use of a VPN, and then only listens on the HTTP port. Navigating to a merge request creation thus results in an error page as lazygit directs to `https://gitlab.domain.top/path`.

**To Reproduce**
Steps to reproduce the behavior:

1. Setup a gitlab service provider that listens only on http
2. Go to 'Local Branches'
3. Select your branch which you want to make a merge request for
4. Press 'o'
5. See error

**Expected behavior**
It should be possible to be directed to a http address instead on an https one.

**Screenshots**
N/A

**Version info:**
```
% lazygit --version
commit=, build date=, build source=homebrew, version=0.36.0, os=darwin, arch=amd64, git version=2.39.1
```
```
% git --version
git version 2.39.1
```