Bug 10690 - Warn about trailing slashes in description of OPACBaseURL and staffClientBaseURL

The descriptions for OPACBaseURL and staffClientBaseURL are not explicit
about including a trailing slash or not. This patch makes it explicit
that the trailing slash should *not* be included.

To test:
- Apply the patch
- Search for "baseurl" in the system preferences
- Check that the description of both sysprefs includes a warning about
  not including a trailing slash.
- Sign off

If you want to check that the trailing slash is in fact superfluous you
can do something like 'grep -r "BaseURL" *' and check that these
sysprefs are usually concatenated with some string that starts with a
slash.

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Changes to the description appear correctly on both system
preferences.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit da40fe77fc)
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>

koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/opac.pref

@@ -9,7 +9,7 @@ OPAC:
             - "The OPAC is located at http://"
             - pref: OPACBaseURL
               class: url
-            - . (This must be filled in correctly for RSS, unAPI, and search plugins to work.)
+            - . Do not include a trailing slash in the URL. (This must be filled in correctly for RSS, unAPI, and search plugins to work.)
         -
             - Show
             - pref: LibraryName

koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/staff_client.pref

@@ -9,7 +9,7 @@ Staff Client:
             - "The staff client is located at http://"
             - pref: staffClientBaseURL
               class: url
-            - .
+            - . Do not include a trailing slash in the URL.
         -
             - Include the stylesheet at
             - pref: intranetstylesheet