renew() - Ensure CA index.txt.attr has 'unique_subject = no'

This is required to support renewal of a certificate.

Closes: #419

Signed-off-by: Richard T Bonhomme <tincantech@protonmail.com>

easyrsa3/easyrsa

@@ -1496,6 +1496,9 @@ Error: didn't find a file base name as the first argument.
 Run easyrsa without commands for usage and command help."
 	crt_in="$EASYRSA_PKI/issued/$1.crt"
 
+	# Upgrade CA index.txt.attr - unique_subject = no
+	up23_upgrade_ca || die "Failed to upgrade CA to support renewal."
+
 	# Append 'nopass'
 	opt_nopass=""
 	if [ "$2" ]; then