Remove nocache code in the cookie scope. It shouldn't be necessary now
with CookieJar and the vary support in the protocol cache.
5.0 compatibility note: The old nocache behavior meant that any rxml
accessing cookies implicitly disabled the protocol cache. That means
the new behavior can introduce overcaching side-effects in old code,
even if the protocol cache entries are cookie specific. Therefore the
nocache behavior is kept if the compat level is <= 4.5.