perl-net-ssleay: fix configure

CCFLAGS needs the same replacement as LDDLFAGS

see http://autobuild.buildroot.net/results/299/299d6fa6b2ccf97987ffd9c99130c25dd55ca9b4/



Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>