Tests: removed HTTP/2 Upgrade-based negotiation tests.

The HTTP/1.1 Upgrade mechanism is no longer specified in the current http2bis.
See also: https://github.com/BishopFox/h2csmuggler

h2.t

diff --git a/h2.t b/h2.t
index 19ffc7c..9e9b8bc 100644
--- a/h2.t
+++ b/h2.t
@@ -26,7 +26,7 @@
 select STDOUT; $| = 1;
 
 my $t = Test::Nginx->new()->has(qw/http http_v2 proxy rewrite charset gzip/)
-	->plan(144);
+	->plan(142);
 
 $t->write_file_expand('nginx.conf', <<'EOF');
 
@@ -145,25 +145,6 @@
 
 ###############################################################################
 
-# Upgrade mechanism
-
-my $r = http(<<EOF);
-GET / HTTP/1.1
-Host: localhost
-Connection: Upgrade, HTTP2-Settings
-Upgrade: h2c
-HTTP2-Settings: AAMAAABkAAQAAP__
-
-EOF
-
-SKIP: {
-skip 'no Upgrade-based negotiation', 2 if $r !~ m!HTTP/1.1 101!;
-
-like($r, qr!Connection: Upgrade!, 'upgrade - connection');
-like($r, qr!Upgrade: h2c!, 'upgrade - token');
-
-}
-
 # SETTINGS
 
 my $s = Test::Nginx::HTTP2->new(port(8080), pure => 1);