Ticket #3022: fix formatting output for ApiAction::clientError and ApiAction::serverError when caller doesn't explicitly pass the format. Format's already available as a member variable, so use it!
Ticket #3022: fix formatting output for ApiAction::clientError and ApiAction::serverError when caller doesn't explicitly pass the format.
Format's already available as a member variable, so use it!

Fixes some error reponses in api/statusnet/groups/leave.json which were coming through as XML.
May fix some others as well.

faulteh/gnu-social,zcopley/StatusNet,charnimda/lgbtpzn-social,sikevux/bsk-social,studio666/gnu-social,foocorp/gnu-social,chimo/social,furtherfield/gnu-social,Piratas/tortuga,chimo/social,gnusocial/mainline,gnusocial/mainline,xebia/statusnet-oauth2,sikevux/bsk-social,gnusocial/mainline,csarven/statusnet,xebia/statusnet-oauth2,eXcomm/gnu-social,sikevux/bsk-social,csarven/statusnet,bankonme/gnu-social,faulteh/gnu-social,foocorp/gnu-social,charnimda/lgbtpzn-social,eXcomm/gnu-social,minmb/statusnet,furtherfield/gnu-social,d3vgru/StatusNet,bankonme/gnu-social,faulteh/gnu-social,foocorp/gnu-social,zcopley/StatusNet,d3vgru/StatusNet,eXcomm/gnu-social,furtherfield/gnu-social,zcopley/zcopleys-statusnet-clone,bankonme/gnu-social,zh/statusnet,UngPirat/freesocial,studio666/gnu-social,studio666/gnu-social,zcopley/zcopleys-statusnet-clone,Piratas/tortuga,studio666/gnu-social,zcopley/StatusNet,charlycoste/StatusNet,csarven/statusnet,Piratas/tortuga,faulteh/gnu-social,gnusocial/mainline,minmb/statusnet,charlycoste/StatusNet,zh/statusnet,bankonme/gnu-social,UngPirat/freesocial,furtherfield/gnu-social,d3vgru/StatusNet,zcopley/zcopleys-statusnet-clone,eXcomm/gnu-social,Piratas/tortuga,minmb/statusnet,charnimda/lgbtpzn-social,charlycoste/StatusNet,zh/statusnet,UngPirat/freesocial,csarven/statusnet,sikevux/bsk-social,chimo/social,xebia/statusnet-oauth2