security/acme-client: Update for CloudFlare DNS-01

[woolfyx]

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Describe the bug
When you try to issue a certificate based on a DNS-01 CloudFlare challenge, it's failed due to a change in a CloudFlare API.

An issue is open for acme.sh project : acmesh-official/acme.sh/issues/2888

An update is required to update the file 'dns_cf.sh'. Tested manually on my opnsense and this fix solve the issue.

[fraenki]

The fix is available in acme.sh 2.8.6, which will be included in the next release of OPNsense.