Fix more warnings on FreeBSD
diff --git a/src/num.c b/src/num.c
index 5207af4..7a4d428 100644
--- a/src/num.c
+++ b/src/num.c
@@ -1549,7 +1549,7 @@
 	return s;
 }
 
-static void bc_num_printNewline() {
+static void bc_num_printNewline(void) {
 	if (vm->nchars >= (size_t) (vm->line_len - 1)) {
 		bc_vm_putchar('\\');
 		bc_vm_putchar('\n');