Free requests array on shutdown

Spotted by Raphael Kubo da Costa

Author: lpereira

lwan.c

@@ -554,6 +554,7 @@ lwan_init(lwan_t *l)
 void
 lwan_shutdown(lwan_t *l)
 {
+ free(l->requests);
  lwan_trie_destroy(l->url_map_trie);
  _thread_shutdown(l);
  _socket_shutdown(l);