use https for DEFAULT_URL in distribute_setup.py (#198)

From issue #198, volinthius writes:
> distribute_setup.py has obsolete DEFAULT_URL, which I think is related to this
> https://mail.python.org/pipermail/distutils-sig/2017-October/031712.html

Signed-off-by: Drew Fustini <drew@pdp7.com>

Author: pdp7

distribute_setup.py

@@ -50,7 +50,7 @@ def quote(arg):
         return os.spawnl(os.P_WAIT, sys.executable, *args) == 0
 
 DEFAULT_VERSION = "0.6.45"
-DEFAULT_URL = "http://pypi.python.org/packages/source/d/distribute/"
+DEFAULT_URL = "https://pypi.python.org/packages/source/d/distribute/"
 SETUPTOOLS_FAKED_VERSION = "0.6c11"
 
 SETUPTOOLS_PKG_INFO = """\