Rewrite workaround: urllib have to be patched early.

Thanks to (un)patching urllib before importing zc.buildout.download no more
M2Crypto cluttering is done.

src/zc/buildout/buildout.py

@@ -37,18 +37,18 @@ import UserDict
 import warnings
 import subprocess
 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 urllib
+  python_open_https = urllib.URLopener.open_https
   import M2Crypto
-  URLopener.open_https = python_open_https
+  urllib.URLopener.open_https = python_open_https
 except ImportError:
   pass
+import zc.buildout.download
+import zc.buildout.easy_install
+
 
 try:
   import slapos.libnetworkcache