Tests: fixed race in stream_status_variable.t on exit.

stream_status_variable.t

diff --git a/stream_status_variable.t b/stream_status_variable.t
index e6bab36..3692eee 100644
--- a/stream_status_variable.t
+++ b/stream_status_variable.t
@@ -94,7 +94,7 @@
 
 my $s = stream('127.0.0.1:' . port(8085));
 stream('127.0.0.1:' . port(8085))->read();
-undef $s;
+$s->io('PROXY INVALID');
 
 $t->stop();