patch: backport WSGIPublisher from Zope4

This is a preliminary commit that only adds a verbatim copy of WSGIPublisher.py

product/ERP5Type/ZopePatch.py

@@ -22,6 +22,7 @@
 
 # Load all monkey patches
 from Products.ERP5Type.patches import backports
+from Products.ERP5Type.patches import WSGIPublisher
 from Products.ERP5Type.patches import HTTPRequest
 from Products.ERP5Type.patches import AccessControl_patch
 from Products.ERP5Type.patches import Restricted

[Julien Muchembled]

Don't modify product/ERP5Type/ZopePatch.py in this commit.