The DB column is currency.currency not currency.currency_code.
Test plan:
Delete a currency
Without this patch, you will get a warning in the logs:
No method currency_code! at
/home/koha/src/koha-tmpl/intranet-tmpl/prog/en/modules/admin/currency.tt
line 148.
And the currency won't be deleted.
With this patch, it will!
It also changes the value of the delete op.
Signed-off-by: Brendan A Gallagher <brendan@bywatersolutions.com>