perl-net-ssleay: fix dependency

this dependency was accidentally removed
by https://git.busybox.net/buildroot/commit/package/perl-net-ssleay?id=da9e06cabc578bf9138e100d1492a2d5f2038415



Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>