update the fs_path to reflect the IP of the interface that recieved the request

kamailio/registrar-role.cfg

@@ -153,7 +153,7 @@ route[ATTEMPT_AUTHORIZATION]
         $var(return_port) = "5060";
     }
 
-    $var(params) = "fs_path=<sip:MY_IP_ADDRESS:" + $var(return_port) + ";lr;received='" + $rz + ":" + $si + ":" + $sp + ";transport=" + $proto + "'>";
+    $var(params) = "fs_path=<sip:" + $Ri + ":" + $var(return_port) + ";lr;received='" + $rz + ":" + $si + ":" + $sp + ";transport=" + $proto + "'>";
 
     ## TODO: fix escaping, some phones send us -- reg-id=1;+sip.instance="urn:uuid:9b8bd513-0e6e-4660-ad5e-5e35d88cc68f";
     ##  and if we can store it but not use it because it looses the escapes (that weren't there...)