Bug 11166: make library filter in funds administration page more precise

Bug 11166: make library filter in funds administration page more precise

In funds administration, admin/aqbudgets.pl, there is a combobox for
filtering by library code.

The bug is that the filter uses a pattern match  instead of equals :
  next unless $budget->{budget_branchcode} =~ m/$filter_budgetbranch/;

In this case, if there is a library with code '1' and one with code '12',
filtering by library '1' will also show funds of library '12'.

Test plan :
- Create a library with code '1' and one with code '12'
- Create funds in both libraries
- Go to admin/aqbudgets.pl
- Filter by branch '12'
=> You see only funds of this library
- Filter by branch '1'
=> You see only funds of this library

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Passes koha-qa.pl, works as advertised

Signed-off-by: Galen Charlton <gmc@esilibrary.com>