[Improvement] Separate protocol and path in gitmodules

[Benedek Rácz <betontalpfa@xxxxxxxxx>]

Hi All,

**The issue**
My problem is based on this post: https://stackoverflow.com/q/40841882/2506522

**Use-case:**
Git can be used with SSH or with HTTP. The usage of SSH is easier, due
to automatic authentication (ssh-key). But I have to use git from a
public PC, where I mustn't store my ssh-keys. On that PC I want to use
https's user/password authentication.

**Suggestion**
The root-cause of this issue is that the protocol (SSH or HTTP) and
the path of the remote repository is stored together (in the
.gitmodules file). If they were stored separately I would choose the
protocol easily.

Benedek