[O] No operator defined for property header-args

[Kevin Foley]

I'm getting the error "No operator defined for property header-args" when
trying to run `org-property-action` on the `header-args` property below:

    * outline header
    :PROPERTIES:
    :header-args:bash:    :tangle yes
    :END:

I'm able to set the same properties using

    #+PROPERTY: header-args:bash :tangle yes

I've tried running `emacs -Q` and get the same error.  I'm using
org-version is 9.0.7