[postgis-devel] Bump GDAL and Proj versions for PostGIS 3

[Christoph Berg]

Re: Even Rouault 2019-07-08 <1601840.ZlCh8DZyrr at even-i700>
> > gdal | 1.11.3+dfsg-3build2  | xenial/universe        | source
> > proj | 4.9.2-2              | xenial/universe        | source
> 
> People can use ubuntugis there:
> https://launchpad.net/~ubuntugis/+archive/ubuntu/ppa
> has
> GDAL 2.2.2 for Xenial

I'm building postgis packages for apt.postgresql.org and I'd hate to
have to tell people to use yet another external repository for stuff
we ship. (And I'd rather also avoid having to build yet more
backports inside our repository.)

Christoph