### Description

usrloc should not leave any ucontact behind when on DB_ONLY

### Troubleshooting

#### Reproduction ``` event_route[usrloc:contact-expired] { $var(uri) = "sip:" + $ulc(exp=>aor) + "@localhost"; xinfo("expired contact for $ulc(exp=>aor) uri:$var(uri)"); reg_fetch_contacts("location", "$var(uri)", "caller"); if($(ulc(caller=>count)) < 0) { xinfo("no more contacts for $ulc(exp=>aor)\n"); } else { xinfo("$ulc(exp=>aor) has $(ulc(caller=>count)) contacts left\n"); } return; } ``` REGISTER a subscriber and let it expire

#### Debugging Data

after

``` root@16d059a62a76:/code/utils/kamcmd# sh /kamdev/shm_dump.sh 1 2 qm_status: alloc'd from usrloc: dlist.c: new_dlist(557) 2 qm_status: alloc'd from usrloc: dlist.c: new_dlist(565) 2 qm_status: alloc'd from usrloc: ucontact.c: new_ucontact(96) 2 qm_status: alloc'd from usrloc: udomain.c: new_udomain(91) 2 qm_status: alloc'd from usrloc: udomain.c: new_udomain(98) 2 qm_status: alloc'd from usrloc: ul_callback.c: init_ulcb_list(45) 2 qm_status: alloc'd from usrloc: ul_callback.c: register_ulcb(94) 6 qm_status: alloc'd from usrloc: udomain.c: build_stat_name(56) 10 qm_status: alloc'd from usrloc: ../../core/ut.h: shm_str_dup(722)

```

#### Log Messages

``` 1(4112) DEBUG: usrloc [udomain.c:996]: udomain_contact_expired_cb(): calling contact expired records - cycle [1] 1(4112) DEBUG: usrloc [ul_callback.h:83]: run_ul_callbacks(): contact=0x7f621e476bd0, callback type 8/8, id 0 entered 1(4112) exec: *** cfgtrace:request_route=[usrloc:contact-expired] c=[/kamdev/kamailio.cfg] l=1015 a=63 n=assign 1(4112) exec: *** cfgtrace:request_route=[usrloc:contact-expired] c=[/kamdev/kamailio.cfg] l=1016 a=25 n=xinfo 1(4112) INFO: <script>: expired contact for 1001-whatever uri:sip:1001-whatever@localhost 1(4112) exec: *** cfgtrace:request_route=[usrloc:contact-expired] c=[/kamdev/kamailio.cfg] l=1017 a=27 n=reg_fetch_contacts 1(4112) exec: *** cfgtrace:request_route=[usrloc:contact-expired] c=[/kamdev/kamailio.cfg] l=1022 a=16 n=if 1(4112) exec: *** cfgtrace:request_route=[usrloc:contact-expired] c=[/kamdev/kamailio.cfg] l=1021 a=25 n=xinfo 1(4112) INFO: <script>: 1001-whatever has 1 contacts left 1(4112) exec: *** cfgtrace:request_route=[usrloc:contact-expired] c=[/kamdev/kamailio.cfg] l=1023 a=2 n=return

```

### Possible Solutions

I think the problem resides on udomain_contact_expired_cb() and using get_urecord(). PR will follow.

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` version: kamailio 5.4.0-dev0 (x86_64/linux) 075c74 flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, 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, TLS_PTHREAD_MUTEX_SHARED ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: 075c74 compiled on 10:36:45 Oct 3 2019 with gcc 8.3.0 ```