* added missing include in hashtable

sys/lib/hashtable.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdint.h>
 #include <math.h>
 #include "hashtable.h"
 #include "hashtable_private.h"