gen_makefile.py: use s#git://#https://# in git clone base URL

Unencrypted git:// protocol offers no integrity or authentication,
making it subject to tampering.  Use https:// instead.

https://github.blog/2021-09-01-improving-git-protocol-security-github/#no-more-unauthenticated-git
https://blog.readthedocs.com/github-git-protocol-deprecation/

Using https:// is also required for some new repositories (like
libosmo-gprs.git), which are intentionally unavailable over git://.

Change-Id: I503f0e1b5258102d771597f1b5b753f670832fcb
1 file changed