Default parameter "-gui" and "-rfbport" make x11vnc failed to start if no
"wish" installed.
[BUGID #781] got fixed.
(From OE-Core rev: 1e1b59cd94a3fb3092b4334cd247d2d18c9e8071)
Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>