Resolver: removed unused field from ngx_resolver_ctx_t.

src/core/ngx_resolver.h

diff --git a/src/core/ngx_resolver.h b/src/core/ngx_resolver.h
index 07fa257..424cd73 100644
--- a/src/core/ngx_resolver.h
+++ b/src/core/ngx_resolver.h
@@ -141,7 +141,7 @@
 struct ngx_resolver_ctx_s {
     ngx_resolver_ctx_t       *next;
     ngx_resolver_t           *resolver;
-    ngx_udp_connection_t     *udp_connection;
+    ngx_resolver_node_t      *node;
 
     /* event ident must be after 3 pointers as in ngx_connection_t */
     ngx_int_t                 ident;
@@ -161,8 +161,6 @@
     ngx_uint_t                quick;  /* unsigned  quick:1; */
     ngx_uint_t                recursion;
     ngx_event_t              *event;
-
-    ngx_resolver_node_t      *node;
 };