[orca-list] the backspace key in gnome shell run dialog seems to be read wrong by orca

[José Vilmar Estácio de Souza <vilmar informal com br>]

To reproduce try the following steps:

1. Press alt+f2.
2. Type 'abcd', without the quotations.
3. Press the home key.
4. Press right arrow one time.
5. Press the backspace key.

Expected results: Orca should read 'a'.
Actual results: Orca reads 'b'.

Instead of read the deleted character by backspace, orca reads the char 
left shifted.

Thanks.
{}S José Vilmar Estácio de Souza