Core: fixed memory leak on error, missed in c3f60d618c17.

Found by Coverity (CID 1451664).

src/core/ngx_hash.c

diff --git a/src/core/ngx_hash.c b/src/core/ngx_hash.c
index d684e70..d9c157c 100644
--- a/src/core/ngx_hash.c
+++ b/src/core/ngx_hash.c
@@ -358,6 +358,7 @@
                           "could not build %s, you should "
                           "increase %s_max_size: %i",
                           hinit->name, hinit->name, hinit->max_size);
+            ngx_free(test);
             return NGX_ERROR;
         }