Hopefully fix Ol 2016 crash on send

* src/mailitem-events.cpp (request_send): Remove delay.

Earlier tests with 2013 made me think that the delay was necessary
here. But Ol 2016 and Ol 2013 work reliably without it.
This makes the code more deterministic (Placing a Window message
in the Queue right after the encryption is done.) and appears
to fix a random crash in Ol 2016 where Outlook Itself would crash
after sending the message.