Bug 30786: Fix capitalization in advanced search system preferences

Bug 30786: Fix capitalization in advanced search system preferences

This fixes the capitalization in the descriptions for the
AdvancedSearchTypes and OpacAdvancedSearchTypes system preferences.

Test plan:
1. In the staff interface, search the system preferences for
   'AdvancedSearch'.
2. Review the current descriptions for the AdvancedSearchTypes and
   OpacAdvancedSearchTypes system preferences.
3. Note that "..Shelving Location.." is used instead of "..Shelving
   location..".
4. Apply the patch.
5. Refresh the page.
6. Sentence case is now used for "Shelving location" in the
   descriptions (as per coding guideline HTML4: Upper and lower cases
   in strings).
7. Sign off.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Sally <sally.healey@cheshiresharedservices.gov.uk>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>