Prevent non-commands being passed to antispam check.

main.go

@@ -414,6 +414,11 @@ func main() {
 			log.Printf("<%s @ %s> %s", event.Nick, target, msg)
 
 			cmd := parseCommand(msg)
+			isCommand := !isChannel || strings.HasPrefix(cmd.Name, "!")
+			if !isCommand {
+				return
+			}
+
 			log.Printf("Antispam check: %s, %s", event.Source, cmd.Name)
 			if ok, duration := antispamInstance.Check(event.Source, cmd.Name); !ok {
 				conn.Noticef(sender, "Sorry, please try again %s.", humanize.Time(time.Now().Add(duration)))