Remove a deprecation warning

* Express 3 deprecated this a while back to a separate package. It is currently default used with POST request response so this probably needs to be kept in. Basically they are forcing this `Vary` header in on all form request responses...e.g. defining a newer type of standard. `'X-HTTP-Method-Override'` is placed in regardless of `methodOverride` parm being used or not. Pkg docs say to use it in intial setup.

Tested on route `'/script/:namespace?/:scriptname/edit'`

See also:
* https://github.com/OpenUserJs/OpenUserJS.org/issues/315#issuecomment-59668729 and forward