use ngx_resolver_alloc() instead of ngx_resolver_calloc()
since all fields are filled

src/core/ngx_resolver.c

diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index 9e6fb51..0352738 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -1728,7 +1728,7 @@
 
     len = sizeof(ngx_resolver_query_t) + nlen + sizeof(ngx_resolver_qs_t);
 
-    p = ngx_resolver_calloc(ctx->resolver, len);
+    p = ngx_resolver_alloc(ctx->resolver, len);
     if (p == NULL) {
         return NGX_ERROR;
     }
@@ -1809,7 +1809,7 @@
           + sizeof(".255.255.255.255.in-addr.arpa.") - 1
           + sizeof(ngx_resolver_qs_t);
 
-    p = ngx_resolver_calloc(ctx->resolver, len);
+    p = ngx_resolver_alloc(ctx->resolver, len);
     if (p == NULL) {
         return NGX_ERROR;
     }