configure: more autostuff compatibility

Ignore --program-prefix=...

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from d28b764334b8f8f3acfecafea3b52a6cc2e8a272)

 reporter_name="Thomas Petazzoni"

 reporter_url="http://www.free-electrons.com/"

 reporter_comment="Very basic testing only"