security/snortsam: Unbreak build on FreeBSD >= 12.1

snortsam.c:750:6: error: conflicting types for 'parseline'
void parseline(char *arg,bool first,char *file,unsigned long line)

^

./snortsam.h:470:6: note: previous declaration is here
void parseline(char *arg,bool first,char *file,unsigned long line);

^

http://beefy6.nyi.freebsd.org/data/121amd64-default/532242/logs/errors/snortsam-2.70_1.log
http://beefy18.nyi.freebsd.org/data/head-amd64-default/p532607_s360211/logs/errors/snortsam-2.70_1.log