ade: configure: Don't ignore caller-supplied arguments

Because we set args to a new value, any arguments passed to
"ade configure" were ignored.

Apertis: https://phabricator.apertis.org/T3978



Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Justin Kim <justin.kim@collabora.com>
Differential Revision: https://phabricator.apertis.org/D6774