Drop unneeded content-type request headers from test requests
Drop unneeded content-type request headers from test requests

Krenair/restbase,gwicke/restbase,inverno/restbase,inverno/restbase,wikimedia/restbase,physikerwelt/restbase,milimetric/restbase,wikimedia/mediawiki-services-restbase,wikimedia/hyperswitch,milimetric/restbase,cscott/restbase,Pchelolo/restbase,cscott/restbase,d00rman/restbase,eevans/restbase,d00rman/restbase,Krenair/restbase,gwicke/restbase,physikerwelt/restbase,eevans/restbase,wikimedia/mediawiki-services-restbase,Pchelolo/restbase,wikimedia/restbase