python, python3: fix unicodedata enabling

A confusion was made when applying commit
c3d539b5 ('host python/python3:
conditionally disable unicodedata') and then commit
73293e88 ('python, python3: enable
unicodedata for host-python, needed by setuptools').

The first commit added the enabling of unicodedata in the host Python
when the target Python is configured with unicodedata, which is
necessary because building the target unicodedata Python module
requires having unicodedata support in the host Python.

The second commit enabled the unicodedata unconditionally in the host
Python, because it is needed by host-setuptools.

However, when the second commit was applied, the logic that consisted
in disabling unicodedate in the host Python when not needed was kept,
which resulted in breaking the build of host-setuptools due to the
lack of unicodedata support in the host python.

This commit fixes that by only leaving the unconditional
--enable-unicodedata in the host Python configuration options, and
therefore removing the problematic conditional --disable-unicodedata.

Fixes:

  http://autobuild.buildroot.org/results/b62/b622fc14776f5a6c26ff0d1fb882f4ae6cccc5d8/



Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>