Issues resolved with saving mailquota for multiple domains

Hello Jeroen,
After our IRC session, I finally found the real problem, which was not
in pykolab at all:
I had forgotten to set the default_quota = 1048576 in the section of
the domain in kolab.conf, and therefore in user_quota,
https://git.kolab.org/pykolab/tree/pykolab/auth/ldap/__init__.py#n894,
default_quota was not set.
After adding it in kolab.conf, everything is fine!

All the best,
  Timotheus