Update rt4.pm.j2

roles/rt4/templates/rt4.pm.j2

@@ -2,7 +2,7 @@
 Set($rtname, '{{ helpdesk_app_name }}');
 Set($LogoLinkURL , 'https://helpdesk.autistici.org/rt/');
 Set($Organization, '{{ helpdesk_organization }}');
-Set($WebDomain, 'helpdesk.{{ domain_public[0] }}');
+Set($WebDomain, 'helpdesk.autistici.org);
 Set($WebPort, 443);
 Set($WebPath, '/rt');
 Set($CanonicalizeRedirectURLs, 1);