Auto generate DH keys on nodes.

# Auto generate DH keys on nodes.

<gnutls:dhfile> - The file containing DH params, no default
<gnutls:dhbits> - The number of bits to use for DH (Diffie Hellman) parameter generation, defaults to 1024. May be 768, 1024, 2048, 3072 or 4096.

https://wiki.inspircd.org/Modules/2.0/ssl_gnutls
