resource: remove the accept header from requests
resource: remove the accept header from requests

This shouldn't be added to all requests. Instead, it is added by the
FetchConfig functions.

ajeddeloh/ignition,AlexNPavel/ignition,coreos/ignition,dgonyeo/ignition,coreos/ignition,higebu/ignition,higebu/ignition,AlexNPavel/ignition,AlexNPavel/ignition,ajeddeloh/ignition,dgonyeo/ignition,higebu/ignition,dgonyeo/ignition,coreos/ignition,ajeddeloh/ignition