Use mark_safe to use html in users list admin

hc/accounts/admin.py

@@ -96,6 +96,7 @@ class HcUserAdmin(UserAdmin):
 
     ordering = ["-id"]
 
+    @mark_safe
     def engagement(self, user):
         result = ""
         num_checks = Check.objects.filter(user=user).count()
@@ -119,6 +120,7 @@ class HcUserAdmin(UserAdmin):
 
     engagement.allow_tags = True
 
+    @mark_safe
     def checks(self, user):
         url = reverse("hc-switch-team", args=[user.username])
         return "<a href='%s'>Checks</a>" % url