pty: Fix byte loss bug when connecting to pty

When trying to print data to the pty, we first check if it is connected.
If not, we try to reconnect, but we drop the pending data even if we
have successfully reconnected; this makes us lose the first byte of the very
first transmission.
This small fix addresses the issue by checking once more if the pty is connected
after having tried to reconnect.

Signed-off-by: Sebastian Tanase <sebastian.tanase@openwide.fr>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
