Fix RRULE generation for timezones
Summary:
libical 3.0.6 is stricter for RRULEs than previous versions and disallows
setting both the COUNT and UNTIL property at the same time. So don't do
that anymore, one is enough.
Reviewers: dfaure, winterz
Reviewed By: winterz
Subscribers: winterz, kde-pim
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D25857