support Z2 BoundPageTemplates, not just Z3's

CHANGES.txt

@@ -4,6 +4,8 @@ CHANGES
 five.customerize 0.4 (unreleased)
 ---------------------------------
 
+Support Zope 2.12's BoundPageTemplateFile.
+
 Fixed deprecation warnings for use of Globals.
 
 Specify all package dependencies.

src/five/customerize/utils.py

@@ -2,15 +2,16 @@
 from AccessControl import Unauthorized
 from Products.PageTemplates.PageTemplateFile import PageTemplateFile as Z2PTF
 from zope.pagetemplate.pagetemplatefile import PageTemplateFile as Z3PTF
-from zope.app.pagetemplate.viewpagetemplatefile import BoundPageTemplate
+from Products.Five.browser.pagetemplatefile import BoundPageTemplate as Z2BPT
+from zope.app.pagetemplate.viewpagetemplatefile import BoundPageTemplate as Z3BPT
 
 
 def isTemplate(obj):
     """ check if the given object is a or is derived from a template class """
     # TODO: we should really check via interfaces, i.e. `providedBy` here,
     #       but the only class using interfaces atm is Z3PTF :(
     return isinstance(obj, Z2PTF) or isinstance(obj, Z3PTF) or \
-        isinstance(obj, BoundPageTemplate)
+        isinstance(obj, Z2BPT) or isinstance(obj, Z3BPT)
 
 
 def findViewletTemplate(viewlet):