[Kolab-devel] 500 Internal Server Error when downloading zips from git.kolab.org

Hello,
for the nightly CentOS builds I am using this script to download the
source rpms and the zip files from git.kolab.org:
https://gist.github.com/tpokorra/5698249

I tried already to put in more breaks, to not overload the server, but
I still get irregularly http 500 errors.

Would you mind checking the server if it shows any hint?
It happened again this morning:

fetching libkolabxml .tar.gz from git.kolab.org
curl --retry 2 --retry-delay 30 -f -o
rpmbuild/SOURCES/libkolabxml-git-master.tar.gz
https://git.kolab.org/libkolabxml/snapshot/libkolabxml-master.tar.gz
[...]
curl: (22) The requested URL returned error: 500 Internal Server Error

Thanks,
  Timotheus