[orca-list] Thunderbird doesn't announce blank line

[Alex ARNAUD <alexarnaud hypra fr>]

Dear all,

Environment:
- Debian Sid updated
- Thunderbird 52.4
- Orca master

When I'm writing an HTML mail and read the line Orca stays silent on 
blank line.

Steps to reproduce:
1) Open Thunderbird (GTK3 here)
2) Write a new mail (here in a new window)
3) Tab until to switch to the message body
4) Write a line of test : "hello word" and press return
5) Press up arrow
6) Press down arrow

Result: Orca stays silent
Expected result: Orca should announce "blank line"

Best regards.
--
Alex ARNAUD
Visual-Impairment Project Manager
Hypra - "Humanizing technology"