Remove the now unused gtktest configure flag and add one for the emacs option
so we're deterministic. Resolves the warning:
WARNING: QA Issue: leafpad: configure was passed unrecognised options: --disable-gtktest
(From OE-Core rev: 522a8e8d332c162a923e8b880b36fc4b12320c87)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>