[Users] Display next on delete

[Keith Edmunds]

Just upgraded to 3.14.1-17-g7518f0. Now, when deleting a message, the next
message is selected but not displayed. Clicking on the (selected) message
in the summary displays the message as expected.

Configuration/Preferences/Display/Summaries has "Open message when
selected" set to "Yes".

(Note: http://www.claws-mail.org/faq/index.php/Interface suggests it
should be set to "Always", but that isn't an option - maybe that page
needs updating).

Keith
-- 
"One can never know for sure what a deserted area looks like" -
George Carlin