[atlas] TLS error when the certificate is expired?

I'm reasonably certain that it has been possible to use 'sslcert'
measurements even when the certificate is expired.

Today, I try to use 'sslcert' with trigger-happy.eu and it fails:

    "alert": {
      "description": 40,
      "level": 2
    },

And no certificate in the JSON output (this is measurement #12166428)

40 is the very general "handshake failure" of
TLS. <https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-6>

Was there a change in Atlas recently? The TLS server does reply:

% gnutls-cli trigger-happy.eu
Processed 167 CA certificate(s).
Resolving 'trigger-happy.eu:443'...
Connecting to '51.254.210.94:443'...
- Certificate type: X.509
- Got a certificate list of 2 certificates.
- Certificate[0] info:
 - subject `CN=trigger-happy.eu', issuer `CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US', serial 0x0359a66c5eb5da799afe079f87416f8d9641, RSA key 2048 bits, signed using RSA-SHA256, activated `2018-01-13 10:46:26 UTC', expires `2018-04-13 10:46:26 UTC', key-ID `sha256:8216c7a7f221f3efcf7e7c3eb1760275d6ebf38d153b74992ee7864147b54435'
	Public Key ID:
		sha1:668c4506a393d9bb633590b68c05d878734d7ffe
		sha256:8216c7a7f221f3efcf7e7c3eb1760275d6ebf38d153b74992ee7864147b54435
	Public key's random art:
		+--[ RSA 2048]----+
		|   +. o++        |
		|  o +*.=..       |
		|   .=o* . . .    |
		|     * B   o     |
		|    . = S   .    |
		|       = .   .   |
		|      +       E  |
		|     . .         |
		|                 |
		+-----------------+

- Certificate[1] info:
 - subject `CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US', issuer `CN=DST Root CA X3,O=Digital Signature Trust Co.', serial 0x0a0141420000015385736a0b85eca708, RSA key 2048 bits, signed using RSA-SHA256, activated `2016-03-17 16:40:46 UTC', expires `2021-03-17 16:40:46 UTC', key-ID `sha256:60b87575447dcba2a36b7d11ac09fb24a9db406fee12d2cc90180517616e8a18'
- Status: The certificate is NOT trusted. The certificate chain uses expired certificate. 
*** PKI verification of server certificate failed...
*** Fatal error: Error in the certificate.
*** handshake has failed: Error in the certificate.