package/perl-net-ssleay: not available for static link

Perl extensions are loaded at runtime with dlopen(), so it does not
make sense to even build extensions that are written in C.

perl-net-ssleay is (partly) written in C, so it is not available when
doing a static build.

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