python,python3: build bluetooth support if bluez-libs selected

python,python3: build bluetooth support if bluez-libs selected

This should hopefully fix the Python3 build on buildbot.

For a while I assumed it may be a build-bot issue, but
then looking through the packages repo [and finding
the bluez package] it looks like, if you try
to build all packages, Python3 detects the bluetooth
headers installed by bluez.

It looks like Python's bluetooth support was somewhat
broken ; it was not detecting the <bluetooth/bluetooth.h>
header, so a backport from Python3 to Python fixed that.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>