Merge branch 'hide_client' into 'master'

Hide client

When domain module is enabled in config, every module has a domain selector now, and changing domain's owner on domain list changes owner for every module. This patch removes client selector when domain module is enabled, because I don't see the point in having a client selector on mail, sites and dns, neither create nor update, because setting client to a different one than domain's owner, if that client try to edit, it will break because it's not domain's owner.