Bug 16539 - Koha::Cache is incorrectly caching single holidays

Bug 16539 - Koha::Cache is incorrectly caching single holidays

This makes the loop add holidays for each bracnh instead of the calling
branch

To test:
I used memcached-tools to view the cache, clear the cache, and wait for
holidays to regnerate

Have a branches with different holidays
Clear the cache
Do a checkout
View the cache - one libraries holidays are repeated for all branches
Apply patch
Clear the cache
Do a checkout
Library holidays are correctly cached

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>