Bug 10936: remove duplicate 'Standard number' option in Advanced search

Bug 10936: remove duplicate 'Standard number' option in Advanced search

This patch removes the duplicate 'Standard number' option
under the more options of the OPAC advanced search correctly
following updates from Katrin.

TEST PLAN
---------
1) Set opacthemes system preference to bootstrap
2) In OPAC, click 'Advanced search'
3) Click 'More options'
4) Check the Keywords dropdown for duplicate 'Standard number'
5) Apply patch
6) Refresh page, and make sure 'More options' is clicked still
7) Check the Keywords dropdown for duplicate 'Standard number'
   -- it's not this time.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>