Be in timezone Europe/Brussels, where, in 2018, the DST switch
happens on 2018-10-28.
Create a recurring event starting on 2018-10-27 until 2018-10-29
at say, 8am
For the days before the 28, the time of the event will be correct
Before this commit though, for the days after the 28,
the meeting time will be shifted by one hour
This is because the rrule took a TZ aware datetime, and generated recurring
event dates with that same TZ, i.e. the one in STD time
After, this commit, all the meetings are well scheduled at 8am,
OPW 1895315
closesodoo/odoo#27985