Bug 32048: Added clear cache routine to delete_holiday_range_repeatable

Bug 32048: Added clear cache routine to delete_holiday_range_repeatable

When adding and deleting holidays, holidays might return
unexpectedly.

To test:
1 - Enter a holiday repeated yearly on a range from the 1st of the month to the 5th
2 - Delete it
3 - Add a new holiday from the 20th to the 25th
4 - When saved, the holiday from the 1st to the 5th is also added again.
5 - Apply patch and restart_all.
6 - Repeat steps 1-3. Notice that the holiday from the 1st to the 5th is no longer added and it has properly been cleared from the cache.
7 - Sign off! :D

Signed-off-by: Salah Ghedda <salah.ghedda@inLibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>