Bug 22947: Markup error in OPAC preferences file

Bug 22947: Markup error in OPAC preferences file

This patch corrects a markup error in the OPAC .pref file which can
cause display problems. The patch also corrects a validator warning by
changing at <tt> to a <code>.

To reproduce the problem, go to Administration -> Global system
preferences -> OPAC.

Run the page through the W3C validation service:
https://validator.w3.org. Either by pasting in the URL for the search
results (if web accessible) or by viewing source, copying, and pasting
into "Validate by Direct Input."

This patch addresses two specific errors:

 - "Unclosed element code."
 - "The tt element is obsolete. Use CSS instead."

To test, apply the patch and try again to reproduce the validation
errors. Those errors should no longer be present. There should be no
visible change to the display.

Signed-off-by: Maryse Simard <maryse.simard@inlibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>