Fix build & set content type for 'empty response' error too
Fix build & set content type for 'empty response' error too

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