The recent environment fixes broke the menuconfig task since it couldn't access
variables like DISPLAY. This patch updates it to use oe.terminal instead
allowing it to work again.
(From OE-Core rev: e876a44fa8ed0aa2e09084c1e7ddfc876c3f981b)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>