wireshark: forcibly disable lua

If host arch = target arch and liblua is in the host the buildsystem
will pick it up and try to use it since it passes basic build tests.
Forcibly disable it, since it causes no build failure, rather runtime
failures because said liblua is not present on the target.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>