[sr-dev] [kamailio/kamailio] kamcmd: fatal error while compiling on FreeBSD-11.0 (#920)

With latest master compiling failed when compiling kamcmd on FreeBSD-11.0.

``` clang -g -m64 -DNAME='"kamcmd"' -DSRNAME='"kamailio"' -DVERSION='"1.5"' -D__OS_freebsd -DRUN_DIR='"/var/run/kamailio/"' -DUSE_READLINE -DMOD_NAME="utils/kamcmd" -c parse_listen_id.c -o parse_listen_id.o clang -g -m64 -DNAME='"kamcmd"' -DSRNAME='"kamailio"' -DVERSION='"1.5"' -D__OS_freebsd -DRUN_DIR='"/var/run/kamailio/"' -DUSE_READLINE -DMOD_NAME="utils/kamcmd" -c kamcmd.c -o kamcmd.o kamcmd.c:46:10: fatal error: 'readline/readline.h' file not found #include <readline/readline.h> ^ 1 error generated. gmake[3]: *** [../../src//Makefile.rules:100: kamcmd.o] Error 1 ```