Tests: HTTP/2 discarded body TODO adjusted, fix committed.

See 8df664ebe037 and 2e61e4b6bcd9 in nginx for details.

h2_request_body.t

diff --git a/h2_request_body.t b/h2_request_body.t
index f453f36..10d37c0 100644
--- a/h2_request_body.t
+++ b/h2_request_body.t
@@ -167,7 +167,7 @@
 # RST_STREAM with zero code received
 
 TODO: {
-local $TODO = 'not yet';
+local $TODO = 'not yet' unless $t->has_version('1.17.4');
 
 $s = Test::Nginx::HTTP2->new();
 $sid = $s->new_stream({ body_more => 1 });