[jhbuild] (6 commits) Non-fast-forward update to branch wip/lantw/support-python3-sysdeps-and-fix-gtk-doc-deps

[Christoph Reiter <creiter src gnome org>]

The branch 'wip/lantw/support-python3-sysdeps-and-fix-gtk-doc-deps' was changed in a way that was not a 
fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  bffe01b... systeminstall: Support 'python3' sysdeps
  56b2fa9... core-deps-latest: gtk-doc depends on pygments

Commits added to the branch:

  d5a43af... core-deps-latest: Update spice-protocol to 0.14.0 (*)
  272741c... core-deps-latest: Update spice-gtk to 0.37 (*)
  d6df9fe... build: Allow building with gettext ≥ 0.20 (*)
  b63ddb8... env: set CMAKE_PREFIX_PATH (*)
  cb7827d... systeminstall: Support 'python3' sysdeps
  7434e2f... core-deps-latest: gtk-doc depends on pygments

(*) This commit already existed in another branch; no separate mail sent