Update DNT SpecData URL, and mark Obsolete (#1324)
Update DNT SpecData URL, and mark Obsolete (#1324)

The DNT spec has been permanently retired as a W3C Note, with the final
URL https://www.w3.org/TR/tracking-dnt/.
a2sheppy/kumascript,jpmedley/kumascript,a2sheppy/kumascript,jpmedley/kumascript