### Description

<!-- Explain what you did, what you expected to happen, and what actually happened. -->

### Troubleshooting 3 insertions works:

`redis_cmd("kam_redis", "SET %s %s-%s", "test_key", "foo", "bar", "r");`

4 does not:

`redis_cmd("kam_redis", "SET %s %s-%s-%s", "test_key", "foo", "bar", "bar2", "r");`

#### Reproduction add this to cfg, run `kamailio -c` `redis_cmd("kam_redis", "SET %s %s-%s-%s", "test_key", "foo", "bar", "bar2", "r");`

#### Log Messages

``` 0(30690) CRITICAL: <core> [core/cfg.y:3517]: yyerror_at(): parse error in config file /etc/kamailio/kamailio.cfg, line 433, column 83: Too many arguments

0(30690) CRITICAL: <core> [core/cfg.y:3517]: yyerror_at(): parse error in config file /etc/kamailio/kamailio.cfg, line 433, column 83: '('')' expected (function call) 0(30690) CRITICAL: <core> [core/cfg.y:3517]: yyerror_at(): parse error in config file /etc/kamailio/kamailio.cfg, line 433, column 83: bad command: missing ';'? 0(30690) ERROR: <core> [core/cfg.y:3363]: yyparse(): function used inside params of another function: xlog 0(30690) CRITICAL: <core> [core/cfg.y:3517]: yyerror_at(): parse error in config file /etc/kamailio/kamailio.cfg, line 435, column 9: use of function execution inside params not allowed

```

### Additional Information

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

``` version: kamailio 5.2.7 (x86_64/linux) flags: STATS: Off, USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, 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_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled with gcc 5.4.0 root@vagrant-ubuntu-xenial-64 ```

* **Operating System**:

Ubuntu 16.04