Changes

OBS: sync_obs_projects: support security.d.o

The Debian 13 meta config in the OpenSUSE OBS now lists
security.debian.org. Adjust the script that syncs the config to support
this URL too, rewrite it to HTTPS just like the other mirror URL.

Fix for:
      changing url to https: http://security.debian.org/debian-security?dist=trixie-security&component=main
  Traceback (most recent call last):
    File "/obs/sync_obs_projects.py", line 322, in <module>
      main()
    File "/obs/sync_obs_projects.py", line 312, in main
      rewrite_meta(project)
    File "/obs/sync_obs_projects.py", line 190, in rewrite_meta
      assert url.startswith("http://ftp.de.debian.org/debian"), \
  AssertionError: unexpected mirror URL

Related: https://build.opensuse.org/projects/Debian:13/meta
Change-Id: Iaf6a025376e398e26c5031b07fee6c1f64cbe047