Generate a random serial from /dev/urandom when creating selfsigned certs. Fixes "sec_error_reused_issuer_and_serial" with Firefox. Signed-off-by: Jo-Philipp Wich <jow@openwrt.org> SVN-Revision: 43168
Signed-off-by: Felix Fietkau <nbd@openwrt.org> SVN-Revision: 40000