VALARM in .ics not respected.

[rekweststory]

*Note: using offline calendars only, since that seems to make a difference.
Create a .ics file, with an event in the future, including
...
BEGIN:VALARM
ACTION:DISPLAY
TRIGGER:-PT45M
DESCRIPTION:
END:VALARM
...
No notification for 45 mins before will be created.
Only the default notification time will be offered.
This means that export/import cannot be used as a work-around to copy events between calendars, nor can Etar be used to backup/restore calendars.

[Gitsaibot]

See #653