fix building by msvc, introduced in r2487
diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index c68c7f4..f58fb5b 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -1531,7 +1531,7 @@
             ngx_resolver_free(r, rn->name);
         }
 
-        rn->nlen = name.len;
+        rn->nlen = (u_short) name.len;
         rn->name = name.data;
 
         name.data = ngx_resolver_dup(r, rn->name, name.len);