Use Python 3 for test web server

The parts of libtest.sh and tests/make-test-runtime.sh that deal with
Python 2 are unaffected: they are only used in the flatpak-builder
tests.

Forwarded: not-needed

Gbp-Pq: Topic debian
Gbp-Pq: Name Use-Python-3-for-test-web-server.patch

flatpak (0.10.4-1) unstable; urgency=medium

  * New upstream release
  * Don't install documents portal or permission store. Depend on
    xdg-desktop-portal (>= 0.10) instead: they have moved there.
  * d/p/Only-require-FUSE-if-we-re-still-building-the-document-po.patch:
    Don't depend on FUSE at build-time

[dgit import unpatched flatpak 0.10.4-1]

Import flatpak_0.10.4.orig.tar.xz

[dgit import orig flatpak_0.10.4.orig.tar.xz]

Import flatpak_0.10.4-1.debian.tar.xz

[dgit import tarball flatpak 0.10.4-1 flatpak_0.10.4-1.debian.tar.xz]