Use string.h instead of strings.h

No idea how the non-standard strings.h header got included

Author: TheDcoder

parse.c

@@ -21,7 +21,7 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <strings.h>
+#include <string.h>
 #include "parse.h"
 #include "utils.h"