Re: [sr-dev] [kamailio/kamailio] dmq: add optional parameter to dmq_handle_message() (#1626)

some context for this PR... we are testing using the `tsilo` module for mobile push notifications while maintaining multiple registrars with `dmq_usrloc` if an `INVITE` goes to a registrar "A" and then the UA registers to registrar "B", the dmq message is sent to registrar "A" with UA location info,and the INVITE can be resumed successfully.

``` if (is_method("KDMQ")) { dmq_handle_message("1"); if ($tU == "usrloc") { $var(a) = ""; json_get_field("$rb", "aor", "$var(a)"); $var(a) = $(var(a){s.strip,1}); #strip quotes $var(a) = $(var(a){s.striptail,1}); #strip quotes $var(p) = "sip:" + $var(a); route(PUSHJOIN); } exit; } ```