Tests: try to load python plugin if uwsgi has no wsgi option.

uwsgi.t

diff --git a/uwsgi.t b/uwsgi.t
index 00e540e..d655f1a 100644
--- a/uwsgi.t
+++ b/uwsgi.t
@@ -56,7 +56,15 @@
 
 END
 
-$t->run_daemon('uwsgi', '--socket', '127.0.0.1:8081',
+my $uwsgihelp = `uwsgi -h`;
+my @uwsgiopts = ();
+
+if ($uwsgihelp !~ /--wsgi-file/) {
+	# uwsgi has no python support, maybe plugin load is necessary
+	push @uwsgiopts, '--plugin', 'python';
+}
+
+$t->run_daemon('uwsgi', '--socket', '127.0.0.1:8081', @uwsgiopts,
 	'--wsgi-file', $t->testdir() . '/uwsgi_test_app.py',
 	'--logto', $t->testdir() . '/uwsgi_log');