[gnome-settings-daemon/wip/benzea/ci] tests: Drop --x11 option as the argument does not exist anymore

[Benjamin Berg <bberg src gnome org>]

commit 9acd7bc55b359983b54d12c3796564d6d457ea73
Author: Benjamin Berg <bberg redhat com>
Date:   Thu Mar 15 18:29:04 2018 +0100

    tests: Drop --x11 option as the argument does not exist anymore

 tests/gsdtestcase.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/gsdtestcase.py b/tests/gsdtestcase.py
index 49234b5c..5c699e97 100644
--- a/tests/gsdtestcase.py
+++ b/tests/gsdtestcase.py
@@ -176,7 +176,7 @@ class GSDTestCase(dbusmock.DBusTestCase):
         klass.mutter_log = open(os.path.join(klass.workdir, 'mutter.log'), 'wb')
         # See https://gitlab.gnome.org/GNOME/mutter/merge_requests/15
         os.environ['XDG_SESSION_TYPE'] = 'x11'
-        klass.mutter = subprocess.Popen(['mutter', '--x11'],
+        klass.mutter = subprocess.Popen(['mutter',],
                                          stdout=klass.mutter_log,
                                          stderr=subprocess.STDOUT)