Long: key-type
Arg: <type>
Help: Private key file type (DER/PEM/ENG)
Protocols: TLS
Category: tls
---
Private key file type. Specify which type your --key provided private key
is. DER, PEM, and ENG are supported. If not specified, PEM is assumed.

If this option is used several times, the last one will be used.
