KolabMailAccess: fixes for non-existent UIDs
KolabMailAccess: fixes for non-existent UIDs

* in kolab_mail_access_local_handle_attach_summary(), do not set an
  error if we have no summary
* in kolab_mail_access_handle_new_from_infodb(), check for non-existent
  mail summaries, insert handle into local hash table only if new
* get summary from handle only if we need to do foldername check

GNOME/evolution-kolab,GNOME/evolution-kolab