Show "Reset password token is invalid" error message immediately on /resource/password/edit

I think it would be less confusing and frustrating to users if we showed the "Reset password token
is invalid" error message immediately when they first get to the /resource/password/edit page
rather than waiting until *after* they've taken the time to enter their new password twice and
submit the form to tell them about the problem.

This behavior also seems more consistent with pull request #1902