dns: fix dns query cache implementation

Author: Ethan-Arrowood

src/cares_wrap.cc

@@ -881,7 +881,7 @@ void ChannelWrap::Setup() {
   /* We do the call to ares_init_option for caller. */
   const int optmask =
       ARES_OPT_FLAGS | ARES_OPT_TIMEOUTMS |
-      ARES_OPT_SOCK_STATE_CB | ARES_OPT_TRIES;
+      ARES_OPT_SOCK_STATE_CB | ARES_OPT_TRIES | ARES_OPT_QUERY_CACHE;
   r = ares_init_options(&channel_, &options, optmask);
 
   if (r != ARES_SUCCESS) {