http: timeout based on time until repsonse headers
http: timeout based on time until repsonse headers

Switch the http timeout to be for repsonse headers and not the entire
transaction.

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