Add a remark on ind-Zariski versus ind-(Zariski localization)

Thanks to Kestutis Cesnavicius for the following discussion

 Does it work for the result of what is now Proposition 6.6?

 I think it does work: it seems to me that in the proof of Prop. 6.6 the
 only part that needs checking that ind-Zariski can be taken in the
 stronger (=ind-(disjoint union of principal open affines)) sense is
 that Lemma 6.5 outputs such maps. The point in the proof of Lemma 6.5
 that needs likewise checking is that Lemma 6.2 similarly outputs even
 ind-(disjoint union of principal open affines), which it does by
 inspection of its proof (and that of Lemma 6.1).

 To ease the job of the reader in checking all this, perhaps it is worth
 replacing ind-Zariski by the stronger ind-(disjoint union of principal
 open affines) (or rather by some name for this type of morphism that is
 less awkward/lengthy) in the statements?

Decided it was not worth the effort to actually go ahead and change all
the lemmas.