Bug 11954 - Clean up currency default files

Bug 11954 - Clean up currency default files

It makes no sense to have TRUNCATE or foreign key checks.

TEST PLAN
---------
1) Back up your database
2) in an mysql client:
     use kohadata;
     SET FOREIGN_KEY_CHECKS=0;
     TRUNCATE currency;
     source /home/mtompset/kohaclone/installer/data/mysql/ru-RU/optional/sample_currency.sql
     SET FOREIGN_KEY_CHECKS=0;
     TRUNCATE currency;
     source /home/mtompset/kohaclone/installer/data/mysql/uk-UA/optional/sample_currency.sql
     SET FOREIGN_KEY_CHECKS=0;
     TRUNCATE currency;
     source /home/mtompset/kohaclone/installer/data/mysql/it-IT/necessari/parameters.sql
     SET FOREIGN_KEY_CHECKS=1;
     QUIT
   -- These should all work without problem.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>