python: remove stale link to "Python for Embedded Systems Site"

python: remove stale link to "Python for Embedded Systems Site"

Reference url is a stale, non existent site that returns a 404, so get rid of it

Change impacts both the manifest files and the scripts that generate the manifests

Run the following from within recipes-devtools/python

../../../scripts/contrib/python/generate-manifest-2.7.py > python-2.7-manifest.inc
../../../scripts/contrib/python/generate-manifest-2.7.py -n > python-native-2.7-manifest.inc

../../../scripts/contrib/python/generate-manifest-3.5.py > python-3.5-manifest.inc
../../../scripts/contrib/python/generate-manifest-3.5.py -n > python-native-3.5-manifest.inc

Signed-off-by: Bob Cochran <openembedded@mindchasers.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>