Specify --host in 027_stream_regress.pl's pg_regress invocation.

The invocation of pg_regress in 027_stream_regress.pl didn't specify the
host. It ends up working on most systems because of connection
defaults. However, on windows it makes the test very slow unless
PG_TEST_USE_UNIX_SOCKETS is used.

The problem is that windows resolves "localhost" to ::0, 127.0.0.1, the server
started only listens on 127.0.0.1.  On windows refused TCP connections are
internally retried a few times, with back-off between tries, taking at least 2
seconds.

Noticed while investigating a complaint about the test's slow speed by Andrew
Dunstan.

Discussion: https://postgr.es/m/20220127220351.kyp3bdaukfytmoqx@alap3.anarazel.de

Author: anarazel

src/test/recovery/t/027_stream_regress.pl

@@ -58,6 +58,7 @@
 system_or_bail($ENV{PG_REGRESS} . " $extra_opts " .
 			   "--dlpath=\"$dlpath\" " .
 			   "--bindir= " .
+			   "--host=" . $node_primary->host . " " .
 			   "--port=" . $node_primary->port . " " .
 			   "--schedule=../regress/parallel_schedule " .
 			   "--max-concurrent-tests=20 " .