libgnt/libgnt

757982d6c981
override the dependency if we're on a new enough version of meson

Testing Done:
Just ran meson to make sure there weren't any errors.

Reviewed at https://reviews.imfreedom.org/r/836/
syntax: regexp
^build(.+)?\/
^obj-.+\/
packaging\/debian\/.+\.substvars$
packaging\/debian\/.debhelper\/
packaging\/debian\/debhelper-build-stamp$
packaging\/debian\/files$
packaging\/debian\/libgnt.+\/
packaging\/debian\/tmp\/