buildroot

python-jinja2: bump to version 2.9.4

While bumping fix async feature related issue:

Both asyncsupport.py and asyncfilters.py use async feature, that is
not available in Python 2 and some features available in Python 3.6.
So in both cases *.py compilation would produce compiler errors.
Hence remove both files after package extraction.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Tested-by: Lionel Flandrin <lionel@svkt.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>