Bug 42154: Bug 38714 hid the "New match check" link in record matching rules

This patch corrects the logic used to determine whether to show the "New
match check" link. I mistakenly changed it to check for the matchpoints
variable instead of the matchchecks variable.

To test, apply the patch and go to Administration -> Record matching
rules.

- Click "New record matching rule" in the toolbar.
- Scroll down to the "Required match checks" section.
- You should see a "New match check" link alongside a "Remove this match
  check" link.
- Go back to the record matching rules main page.
- If necessary, create a rule which doesn't have any match checks.
- In the "Required match checks" section of the edit form you should see
  a "New match check" link, previously hidden by Bug 388714.

Sponsored-by: Athens County Public Libraries
Signed-off-by: David Nind <david@davidnind.com>

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>

koha-tmpl/intranet-tmpl/prog/en/modules/admin/matching-rules.tt

@@ -327,7 +327,7 @@
             <fieldset class="rows" id="match_checks">
                 <h4>Required match checks</h4>
                 [% IF ( edit_matching_rule ) %]
-                    [% SET p_style = matchpoints ? 'display:none;' : 'display:block;' %]
+                    [% SET p_style = matchchecks ? 'display:none;' : 'display:block;' %]
                     <p id="addMatchCheck" style="[% p_style | html %]">
                         <a href="#" class="btn btn-link" onclick="InsertMatchcheck('mc_1', 'mc_template'); return false;"><i class="fa fa-plus" aria-hidden="true"></i> New match check</a></p
                     >