postfix: add rt4mailgate support

postfix/defaults/main.yml

@@ -26,3 +26,8 @@ postfix_network_access:
   - cidr: 134.130.5.32/27  # rwth
     action: permit
 postfix_content_filter: false  # or: spamassassin
+
+postfix_aliases_rt: []
+#  - queue: IT
+#    url: https://rt.example.com
+#    address: it