T1268: Fix bug where forever recurring events could not be displayed
Summary:
Actually it sets the internal end time interval to 100 years for all kind
of events. Before it was 100 for yearly events, but only 10 for weekly.
Fixes T1268.
Reviewers: Roundcube Kolab Plugins Developers
Maniphest Tasks: T1268
Differential Revision: https://git.kolab.org/D203