Tests: fixed h2_proxy_request_buffering_redirect.t on old versions.

h2_proxy_request_buffering_redirect.t

diff --git a/h2_proxy_request_buffering_redirect.t b/h2_proxy_request_buffering_redirect.t
index 06ad92a..3617a44 100644
--- a/h2_proxy_request_buffering_redirect.t
+++ b/h2_proxy_request_buffering_redirect.t
@@ -72,9 +72,14 @@
 
 # unbuffered request body
 
+SKIP: {
+skip 'leaves coredump', 1 unless $t->has_version('1.17.4')
+	or $ENV{TEST_NGINX_UNSAFE};
+
 TODO: {
-todo_skip 'leaves coredump', 1 unless $ENV{TEST_NGINX_UNSAFE}
-	or $t->has_version('1.17.4');
+local $TODO = 'not yet' unless $t->has_version('1.17.4');
+
+$t->todo_alerts() unless $t->has_version('1.17.4');
 
 my $s = Test::Nginx::HTTP2->new();
 my $sid = $s->new_stream({ body_more => 1 });
@@ -89,4 +94,6 @@
 
 }
 
+}
+
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