Bug#949572: debian-installer: Do not install Python2 by default.

[Witold Baryluk <witold.baryluk@gmail.com>]

Package: debian-installer
Followup-For: Bug #949572

I was thinking maybe it is being installed because of the
Priority: important or Priority: essential, but no I checked
python{,2}{,-minimal} and they are either Priority: standard
and Priority: optional.

So I a not exactly sure what decides to install it.

I checked the debootstrap sources and a profile for 'sid',
I do not see the python mentioned there explicitly.

I even done a test with `debootstrap sid ....` and it doesn't
install Python at all. There is no python in base or required
packages.

So the fact that debian-installer is installing Python2 must be
coming from somewhere else. Python3 makes sense as it is dependency
of reportbug, popcon and apt-listchanges for example.

Cheers,
Witold