[pygobject] tests: fix tests with glib master

[Christoph Reiter <creiter src gnome org>]

commit 6033ab41cdf3ec8d7e689e2a3ea832ed5dfdcf8b
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Sun Nov 15 13:32:30 2020 +0100

    tests: fix tests with glib master
    
    GFileIcon asserts that it gets a file now:
    https://gitlab.gnome.org/GNOME/glib/-/commit/e2fbb74301

 tests/test_gobject.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/tests/test_gobject.py b/tests/test_gobject.py
index 77d788ad..f5a65bba 100644
--- a/tests/test_gobject.py
+++ b/tests/test_gobject.py
@@ -833,7 +833,8 @@ def test_list_properties():
 
     assert list_props("GFileIcon") == list_props(Gio.FileIcon)
     assert list_props(Gio.FileIcon.__gtype__) == list_props(Gio.FileIcon)
-    assert list_props(Gio.FileIcon()) == list_props(Gio.FileIcon)
+    assert list_props(Gio.FileIcon(
+        file=Gio.File.new_for_path('.'))) == list_props(Gio.FileIcon)
 
     for obj in [Gio.ActionEntry, Gio.DBusError, 0, object()]:
         with pytest.raises(TypeError):