[FIX] odoo80: Fix pypa/setuptools#942
Avoid the following traceback:
Generated script '/home/user/plone/zinstance/bin/buildout'.
Traceback (most recent call last):
File "bin/buildout", line 13, in <module>
import zc.buildout.buildout
File "/home/user/.buildout/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/buildout.py", line 18, in <module>
import zc.buildout.easy_install
File "/home/user/.buildout/eggs/zc.buildout-2.5.3-py2.7.egg/zc/buildout/easy_install.py", line 26, in <module>
import pkg_resources
File "/home/user/.buildout/eggs/setuptools-34.0.1-py2.7.egg/pkg_resources/__init__.py", line 72, in <module>
import packaging.requirements
File "/home/user/.buildout/eggs/packaging-16.8-py2.7.egg/packaging/requirements.py", line 59, in <module>
MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
TypeError: __call__() takes exactly 2 arguments (1 given)
Similar to https://github.com/Vauxoo/docker-odoo-image/pull/189