mini-x-session: use x-terminal-emulator

Don't hardcode matchbox-terminal, but use the alternative.

(From OE-Core rev: 0f04855243cb4a0bc4a60d7fb6bf47eef29043cf)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-graphics/mini-x-session/files/mini-x-session

@@ -35,5 +35,6 @@ xrandr -s 1024x768
 # Default files to run if $HOME/.mini_x/session or /etc/mini_x/session
 # dont exist. 
 
-matchbox-terminal&
+x-terminal-emulator &
+
 exec matchbox-window-manager