The parameter has not had any effect in the code since
the dual stack PXE work went into place with Ironic as options
are now generated and transmitted to Neutron for both IPv4 and
IPv6. This option is only used by the internal
``dhcp_options_for_instance`` method in
``ironic.common.pxe_utils`` as a fallback if the calling method
does not specify a version. However a later change resulted in the
default behavior calling the dhcp option generation explicitly
to generate both IPv4 and IPv6 parameters, making the option
entirely redundant.
Third party drivers using the ``dhcp_options_for_instance`` method
should consider generating options for both IPv4 and IPv6 at all
times. See change
If7a296001e204ae0c9a49495731052ab33379628 for examples on how
to do this.
Change-Id: I343783389105f008ce6dafc8d25d93211710771a
