Firefox ESR 31 needs a Python with HTTPSHandler enabled

Using the Python we are currently building for compiling ESR 24 gives

Installing setuptools, pip...
  Complete output from command /home/gk/asan/mozill...ualenv/bin/python2.7 -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip:
  Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/gk/asan/mozilla-beta/python/virtualenv/virtualenv_support/pip-1.5.4-py2.py3-none-any.whl/pip/__init__.py", line 10, in <module>
  File "/home/gk/asan/mozilla-beta/python/virtualenv/virtualenv_support/pip-1.5.4-py2.py3-none-any.whl/pip/util.py", line 18, in <module>
  File "/home/gk/asan/mozilla-beta/python/virtualenv/virtualenv_support/pip-1.5.4-py2.py3-none-any.whl/pip/_vendor/distlib/version.py", line 14, in <module>
  File "/home/gk/asan/mozilla-beta/python/virtualenv/virtualenv_support/pip-1.5.4-py2.py3-none-any.whl/pip/_vendor/distlib/compat.py", line 31, in <module>
ImportError: cannot import name HTTPSHandler

when trying to compile ESR 31. We need to install the libssl-dev package when building Python in gitian-utils.yml