Use the new parameter immediate-forwarding-numbers to configure
immediate forwarding logic that emulates hunt groups

The parameter syntax is:

[<span-name>:]<number>

Multiple elements can be specified separated by commas

If the <span-name> is specified, the span will be checked for
availability, if available, its number will be selected for
forwarding, otherwise next number will be checked

Forwarding is enabled as soon as a channel is answered and its
disabled when the channel is hung up