backward compatibility for zope 2.7

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@21233 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/MailTemplates/MTMultipart.py

@@ -9,7 +9,10 @@ from email import Encoders
 from email.MIMEBase import MIMEBase
 from email.MIMEMultipart import MIMEMultipart
 from Globals import InitializeClass
-from zope.app.content_types import guess_content_type
+try:
+  from zope.app.content_types import guess_content_type
+except ImportError:
+  from OFS.content_types import guess_content_type # Zope 2.7
 from OFS.Image import File
 from ZPublisher.HTTPRequest import FileUpload