Django 3.1 supports relative paths for static_url.
Use it to make it more flexible.
Minor fixes for upgrade:
* ignore-fail-on-non-empty for rmdir /usr/share/etesync-server/etesync_server
* do not stop service (it is stopped already and init file is removed)

Signed-off-by: Peter Stadler <peter.stadler@student.uibk.ac.at>

* Replace creating an empty PYTHON3_PKG_DIR with setting filespec to an
  empty value

* Disable the default Python package build recipe (with
  PYTHON3_PKG_BUILD:=0) and set an empty Build/Compile

* Remove VARIANT:=python3 and PROVIDES (providing the same name as the
  package)

* Add PKG_BUILD_PARALLEL:=1

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

Setup pyhton3-django-etesync-journal using uWSGI with Nginx.

Signed-off-by: Peter Stadler <peter.stadler@student.uibk.ac.at>