Bug 40370: Remove incorrect DB audit instruction and fix HTML formatting

This change removes the incorrect instruction from about.pl:
"Run the following SQL to fix the database" and fixes the HTML
formatting so that the line "-- Convert schema '' to '':;" is
displayed correctly at the start of the line.

Test plan:
0. Apply the patch
1. Go to http://localhost:8081/cgi-bin/koha/about.pl?tab=database
2. Note that "Run the following SQL to fix the database" no
longer appears and "--Convert schema '' to '':;" starts
at the beginning of the line instead of with leading whitespaces.

Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
(cherry picked from commit 6699bdb142)
Signed-off-by: Paul Derscheid <paul.derscheid@lmscloud.de>

koha-tmpl/intranet-tmpl/prog/en/modules/about.tt

@@ -806,11 +806,7 @@
         </div>
         [% IF db_audit.diff_found %]
             <div>
-                <p>Run the following SQL to fix the database:</p>
-                <pre>
-                    <code>[% db_audit.diff | $raw %]</code>
-                </pre
-                >
+                <pre><code>[% db_audit.diff | $raw %]</code></pre>
             </div>
         [% END %]
     [% END # tab=database %]