docker: Avoid "Failed prop type" warning
docker: Avoid "Failed prop type" warning

The check box in Storage's `DriveBox` component does not handle clicks
(onChanged) by itself, but let's the parent element do that, so that the
clickable area is bigger.

Provide a dummy handler, so that React stops complaining about it:

    Warning: Failed prop type: You provided a `checked` prop to a form field without an `onChange` handler. This will render a read-only field. If the field should be mutable use `defaultChecked`. Otherwise, set either `onChange` or `readOnly`.
        in input (created by DriveBox)
        in td (created by DriveBox)
        in tr (created by DriveBox)
        in tbody (created by DriveBox)
        in table (created by DriveBox)
        in div (created by DriveBox)
        in div (created by DriveBox)
        in div (created by DriveBox)
        in DriveBox

An alternative is to add `readOnly`, but that makes the check box appear
grayed out, which we don't actually want.

martinpitt/cockpit,cockpituous/cockpit,andreasn/cockpit,mvollmer/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,cockpituous/cockpit,deryni/cockpit,moraleslazaro/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,deryni/cockpit,garrett/cockpit,deryni/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,cockpituous/cockpit,deryni/cockpit,deryni/cockpit,moraleslazaro/cockpit,andreasn/cockpit,garrett/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,deryni/cockpit,andreasn/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,deryni/cockpit,garrett/cockpit,andreasn/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,andreasn/cockpit,martinpitt/cockpit,mvollmer/cockpit,cockpituous/cockpit,garrett/cockpit,cockpituous/cockpit,andreasn/cockpit,cockpituous/cockpit,martinpitt/cockpit,andreasn/cockpit,cockpit-project/cockpit,mvollmer/cockpit,garrett/cockpit