Remove old User#miq_group deprecation
Remove old User#miq_group deprecation

This isn't possible to continue using with tenancy changes, and was
initially introduced in May 2014 (pre OSS, 3-4 releases ago...)
(transferred from ManageIQ/manageiq@ebda0abbd5ac91be2c05b99b99573ba973f86d05)

ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic