Crash due to RecurringDatePicker setHour

RecurringDatePicker sets HOUR_OF_DAY, however DatePicker design is kind of
broken and it internally uses HOUR or HOUR_OF_DAY depending of the isLatin()
flag. This does not make much sense as in Calendar itself HOUR, HOUR_OF_DAY and
AM_PM are all interconnected.

as DatePicker already has getHourOfDay, add setHourOfDay and set the hours
correctly and let Calendar take care of inconsistencies.

This fixes a crash in the recurring date picker. The crash does not seems to affect
Spacewalk master on Fedora 19, but it seems that some Calendar implementations do not
behave the same.