test wildcard tail hash existance for IPv6 addresses,
the same fix for IPv4 addresses has been made in r2581

src/http/ngx_http.c

diff --git a/src/http/ngx_http.c b/src/http/ngx_http.c
index 0cebf29..9ca52b9 100644
--- a/src/http/ngx_http.c
+++ b/src/http/ngx_http.c
@@ -1870,8 +1870,8 @@
         if (addr[i].hash.buckets == NULL
             && (addr[i].wc_head == NULL
                 || addr[i].wc_head->hash.buckets == NULL)
-            && (addr[i].wc_head == NULL
-                || addr[i].wc_head->hash.buckets == NULL))
+            && (addr[i].wc_tail == NULL
+                || addr[i].wc_tail->hash.buckets == NULL))
         {
             continue;
         }