Bug 766: Remove CGI::scrollinglist from marctagstructure.pl

Bug 766: Remove CGI::scrollinglist from marctagstructure.pl

This patch removes the only instance in this file.

Don't know if the feature is of some utility, seems
that does not work (no use of auth values as indicators
on MARC editor)

To test:
1. Apply the patch
2. Go to Administration > MARC frameworks
3. Clic on MARC structure of any fw
4. Clic Edit on any tag
5. On tag editor check the pulldown 'Authorised value', that was replaced
6. Check for regressions: select a value, save, verify the value, change
again, etc.

Note: removed a SELECT, using now C4::Koha::GetAuthorisedValueCategories
Do not we need an AuthorisedValues.pm? (on C4 or Koha)

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described, passes tests and QA script.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>