[sr-dev] [kamailio/kamailio] not properly compassion (#2701)

### Description

I think something wrong with integer comparison when tested this config file ``` listen=udp:[::1]:5060 listen=udp:127.0.0.1:5060 loadmodule "xlog.so" loadmodule "sdpops.so"

request_route { if (sdp_get_address_family() ieq 6 ) { xlog("L_WARN", "sdp_get_address_family == 6\n"); } else if (sdp_get_address_family() ieq 4) { xlog("L_WARN", "sdp_get_address_family == 4\n"); } else if (sdp_get_address_family() ieq 1) { xlog("L_WARN", "cannot detect sdp family\n"); } } ```

The expected output of IP address type used in SDP. But really I always get "cannot detect sdp family" message.