[orca] Ignore new "busy" event for editable content in Thunderbird

[Joanmarie Diggs <joanied src gnome org>]

commit 9aa40dba5c7bc055df9b608a0ca9bd37138ec0c3
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Tue Mar 27 08:15:21 2018 -0400

    Ignore new "busy" event for editable content in Thunderbird

 src/orca/scripts/apps/Thunderbird/script.py |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/orca/scripts/apps/Thunderbird/script.py b/src/orca/scripts/apps/Thunderbird/script.py
index 4e46166..b4ff020 100644
--- a/src/orca/scripts/apps/Thunderbird/script.py
+++ b/src/orca/scripts/apps/Thunderbird/script.py
@@ -193,6 +193,9 @@ class Script(Gecko.Script):
     def onBusyChanged(self, event):
         """Callback for object:state-changed:busy accessibility events."""
 
+        if self.utilities.isEditableMessage(event.source):
+            return
+
         obj = event.source
         if self.utilities.isDocument(obj) and not event.detail1:
             try: