Fix duplicate standalone_network_plugin_ip_version
Fix duplicate standalone_network_plugin_ip_version

in the generated sample configuration.  This option is deprecated
and should no longer have a ``deprecated_group`` setting.

So remove it.

TrivialFix

Change-Id: Ie24bab0f51d2bd1434593eb0d2f3b65b88904a78

openstack/manila,openstack/manila,bswartz/manila,bswartz/manila