Tests: avoid ssl_certificate.t hang on SIGPIPE.

It could stuck in SSL shutdown after abrupt connection termination by nginx.

A similar change is applied to stream_ssl_certificate.t for consistency.

ssl_certificate.t

diff --git a/ssl_certificate.t b/ssl_certificate.t
index 43ce4ce..ff49eee 100644
--- a/ssl_certificate.t
+++ b/ssl_certificate.t
@@ -198,6 +198,9 @@
 sub get {
 	my ($host, $port, $ctx) = @_;
 	my ($s, $ssl) = get_ssl_socket($host, $port, $ctx) or return;
+
+	local $SIG{PIPE} = 'IGNORE';
+
 	Net::SSLeay::write($ssl, 'GET / HTTP/1.0' . CRLF . CRLF);
 	my $r = Net::SSLeay::read($ssl);
 	Net::SSLeay::shutdown($ssl);

stream_ssl_certificate.t

diff --git a/stream_ssl_certificate.t b/stream_ssl_certificate.t
index 59a4d27..0676f4b 100644
--- a/stream_ssl_certificate.t
+++ b/stream_ssl_certificate.t
@@ -175,6 +175,9 @@
 sub get {
 	my ($host, $port, $ctx) = @_;
 	my ($s, $ssl) = get_ssl_socket($host, $port, $ctx) or return;
+
+	local $SIG{PIPE} = 'IGNORE';
+
 	my $r = Net::SSLeay::read($ssl);
 	Net::SSLeay::shutdown($ssl);
 	$s->close();