Deno ListenOptions hostname does not bind to ipv6 by default

[itspa1]

When a hostname is not provided to a method the ListenOptions defaults it to 0.0.0.0, the process binds to only ipv4 address and for binding an ipv6 address it requires explicit mentioning via the hostname, for example, the hostname should be set to [::1] to bind it to an ipv6 address and so on. Need to check whether to bind the ipv6 address by default, or keep the same functionality as of now.