security/testssl.sh: Fix certificate expiration check

Upstream commit af6ca18933ffc5bb02d2ced46342b8d7a6275acd dropped the
TZ offset from the certificate enddate but the FreeBSD date format was
not updated accordingly. Remove the unnecessary %z from the format
string.

• While here add NO_ARCH

PR: 226676
Submitted by: Piotr Kubaj <pkubaj@anongoth.pl>