Bug 35686: Case missing from installer step 3 template title

This patch adds a missing case to the display of the title on step 3 of
the web installer. This resulted in an empty first part of the title:
" > Web installer > Koha"

To test, apply the patch and reset the database version from the command
line in Koha Testing Docker:

> koha-mysql kohadev
> UPDATE systempreferences SET value = '23.1200002 WHERE variable = 'version';
> quit
> Restart all

- Go to the staff interface. You should be taken to the web installer.
- Log in to the web installer and proceed through until you get to the
  "Updating database structure" page.
- Confirm that the page title is correct.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 5dbab83597)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>

koha-tmpl/intranet-tmpl/prog/en/modules/installer/step3.tt

@@ -20,6 +20,9 @@
             [% t("Install basic configuration settings") | html %]
        [% END %]
     [% END %]
+    [% IF ( updatestructure ) %]
+        [% t("Updating database structure") | html %]
+    [% END %]
     [% IF ( choosemarc ) %]
         [% t("Select your MARC flavor") | html %]
     [% END %]