LDAP: DPD doesn't catch connections starting with ExtendedRequest

Slack user Guy Dom reported this:

Hi, any idea why the LDAP DPD only recognizes LDAP connections whose first operation is a BindRequest? A valid LDAP connection can also start with an ExtendedRequest (0x77), for example when the client immediately requests StartTLS. This means that LDAP traffic on non-standard ports may not be recognized by DPD in that case.

They also provided a pcap that reproduces the issue: ldap_ssl.pcap.zip