[orca] Fix unintentional pruning of children from _getSubtree()

[Joanmarie Diggs <joanied src gnome org>]

commit c91cd7b07cddf3ce74a441e82ea492eb35acbd8d
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Thu Sep 26 17:26:25 2019 +0200

    Fix unintentional pruning of children from _getSubtree()

 src/orca/script_utilities.py | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/orca/script_utilities.py b/src/orca/script_utilities.py
index 50440dcd2..1432ffbe3 100644
--- a/src/orca/script_utilities.py
+++ b/src/orca/script_utilities.py
@@ -5292,6 +5292,9 @@ class Utilities:
             if endObj in subtree:
                 break
 
+        if endObj == startObj:
+            return subtree
+
         try:
             endIndex = subtree.index(endObj)
         except ValueError: