Adapt the register_cover to the new datamodel

aleksis/apps/alsijil/tasks.py

@@ -159,6 +159,9 @@ def generate_full_register_printout(
     # build the query-set
     group = Group.objects.filter(pk=group)
 
+    if include_cover:
+        group = group.select_related("school_term")
+
     if include_teachers_and_subjects_table:
         group = group.prefetch_related(
             "courses",

aleksis/apps/alsijil/templates/alsijil/partials/register_cover.html

 <div class="center-align">
   <h1>{% trans 'Class register' %}</h1>
-  <h5>{{ school_term }}</h5>
-  <p>({{ school_term.date_start }}–{{ school_term.date_end }})</p>
+  <h5>{{ group.school_term }}</h5>
+  <p>({{ group.school_term.date_start }}–{{ group.school_term.date_end }})</p>
   {% static "img/aleksis-banner.svg" as aleksis_banner %}
   <img src="{% firstof SITE_PREFERENCES.theme__logo.url aleksis_banner %}"
        alt="{{ SITE_PREFERENCES.general__title }} – Logo" class="max-size-600 center">