Workaround M2Crypto bug of https redirection.

src/zc/buildout/buildout.py

@@ -40,6 +40,16 @@ import zc.buildout
 import zc.buildout.download
 import zc.buildout.easy_install
 
+# Workaround for https://bugzilla.osafoundation.org/show_bug.cgi?id=13033
+# M2Crypto breaks https links
+try:
+  from urllib import URLopener
+  python_open_https = URLopener.open_https
+  import M2Crypto
+  URLopener.open_https = python_open_https
+except ImportError:
+  pass
+
 try:
   import slapos.libnetworkcache
 except ImportError: