byte-compile-nogroup-warn effectively disabled

[Richard M Stallman]

This change

     ;; Warn if a custom definition fails to specify :group.
     (defun byte-compile-nogroup-warn (form)

    +  (if (and (memq (car form) '(custom-declare-face custom-declare-variable))
    +           byte-compile-current-group)
    +      ;; The group will be provided implicitly.
    +      nil

effectively defeats the point of that warning, which is to
make sure that every defcustom and defface specifies the group.