Fix no "Register" tab if ldap auth is enabled (#24038)

This commit is dedicated to GuilhemB, thanks for supporting me on Tipeee
:-)

app/views/devise/shared/_tabs_ldap.html.haml

@@ -8,3 +8,6 @@
   - if signin_enabled?
     %li
       = link_to 'Standard', '#ldap-standard', 'data-toggle' => 'tab'
+  - if signin_enabled? && signup_enabled?
+    %li
+      = link_to 'Register', '#register-pane', 'data-toggle' => 'tab'

changelogs/unreleased/24038-fix-no-register-pane-if-ldap.yml

+---
+title: Fix no "Register" tab if ldap auth is enabled (#24038)
+merge_request: 7274
+author: Luc Didry