Only show the site_nav_object block if Action::showObjectNav has been overridden to do something.
Only show the site_nav_object block if Action::showObjectNav has been overridden to do something.

(Copied similar check from showPageNoticeBlock, handy!)

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