peer-groups does not accept send-software-version

[robbat2]

{"Error":"1 error(s) decoding:\n\n* 'peer-groups[0].config' has invalid keys: send-software-version","Topic":"Config","level":"fatal","msg":"Can't read config file /etc/gobgpd.conf","time":"xxx"}

$ gobgp --version
gobgp version 3.23.0

partial config to reproduce:

[[peer-groups]]
  [peer-groups.config]
    peer-group-name = "test"
    peer-as = 1234
    send-software-version = true

[[neighbors]]
  [neighbors.config]
    neighbor-address = "1.2.3.4"
    peer-group = "test"

This config works:

[[peer-groups]]
  [peer-groups.config]
    peer-group-name = "test"
    peer-as = 1234

[[neighbors]]
  [neighbors.config]
    neighbor-address = "1.2.3.4"
    peer-group = "test"
    send-software-version = true