### Description 1. Added 3 gateways to the dispatcher list file: ``` 1 sip:naptr.mydomain.net 0 0 2 sip:srv.mydomain.net 0 0 ``` started kamailio and ran: ```kamcmd dispatcher.list``` Output: ```error: 500 - No Destination Sets``` If I append to the list, one gateway which resolves to an A record (or an IP:PORT format) like e.g.: ```3 sip:a.mydomain.net:5060 0 0```, it shows up in the dispatcher list just fine: ``` { NRSETS: 1 RECORDS: { SET: { ID: 3 TARGETS: { DEST: { URI: sip:a.mydomain.net:5060 FLAGS: AP PRIORITY: 0 LATENCY: { AVG: 14.642 STD: 0.05 EST: 15.0345 MAX: 25.452 TIMEOUT: 0 } } } } } } ```

I also verified the DNS resolution with: ```kamcmd dns.lookup naptr naptr.mydomain.net``` and ```kamcmd dns.lookup srv srv.mydomain.net``` which was perfectly as expected.

Since I wasn't even able to see a dispatcher loaded, there was no operation that I could do to it to set it to active or anything else.

A network trace just shows A record queries to all gateways with no success on those which have NAPTR/SRV records.

#### Reproduction 100% reproducible with the description above.

### Additional Information

Tested on Kamailio version 4.4.5 and 5.1.1 with the following detailed version info:

``` version: kamailio 5.1.1 (x86_64/linux) flags: STATS: Off, USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MEM, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES ADAPTIVE_WAIT_LOOPS=1024, MAX_RECV_BUFFER_SIZE 262144, MAX_LISTEN 16, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. compiled with /usr/bin/gcc 4.1.2 ```