kamailio presence: use $subs(uri)

use $subs(uri) to better handle resubscriptions

kamailio/presence-role.cfg

@@ -77,7 +77,7 @@ route[HANDLE_SUBSCRIBE]
            $var(fs_contact) = $var(fs_contact) + ";" + $(ct{tobody.params});
         }
 
-        $var(amqp_payload_request) = '{"Event-Category" : "presence", "Event-Name" : "subscription", "Event-Package" : "$hdr(event)", "Expires" : "$var(Expires)", "Queue" : "BLF-MY_HOSTNAME", "Server-ID" : "BLF-MY_HOSTNAME" , "Contact" : "$(ct{s.escape.common})", "Call-ID" : "$ci", "From" : "$fu", "User" : "$tu", "User-Agent" : "$(ua{s.escape.common})" }';
+        $var(amqp_payload_request) = '{"Event-Category" : "presence", "Event-Name" : "subscription", "Event-Package" : "$hdr(event)", "Expires" : "$var(Expires)", "Queue" : "BLF-MY_HOSTNAME", "Server-ID" : "BLF-MY_HOSTNAME" , "Contact" : "$(ct{s.escape.common})", "Call-ID" : "$ci", "From" : "$fu", "User" : "$subs(uri)", "User-Agent" : "$(ua{s.escape.common})" }';
 
         kazoo_publish("dialoginfo_subs", "dialoginfo_subs", $var(amqp_payload_request));