[orca] Fix another regression which resulted from the MATE Panel hackaround

[Joanmarie Diggs <joanied src gnome org>]

commit 7076261a5a8aaea4b8c62c0b78dc9ead7826ea99
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Tue Mar 14 02:29:02 2017 -0400

    Fix another regression which resulted from the MATE Panel hackaround

 src/orca/scripts/default.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/orca/scripts/default.py b/src/orca/scripts/default.py
index c66aa05..92c8ae6 100644
--- a/src/orca/scripts/default.py
+++ b/src/orca/scripts/default.py
@@ -2441,7 +2441,7 @@ class Script(script.Script):
             return
 
         window, dialog = self.utilities.frameAndDialog(obj)
-        if not self.utilities.canBeActiveWindow(window) and not dialog:
+        if window and not self.utilities.canBeActiveWindow(window) and not dialog:
             return
 
         try: