Bug 32294: Fix capitalization for user ID in self checkout

Bug 32294: Fix capitalization for user ID in self checkout

Fixes capitalization of "user ID" on the self checkout help
page.

To test:
* Enable WebBasedSelfCheck
* Go to: /cgi-bin/koha/sco/sco-main.pl in the OPAC
* Log in and open help
* Verify there is a User ID within a sentence and a User id in the heading
* Apply patch
* Both should be corrected

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>