Prevent KeyError on Zope2.7.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@18725 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/PDFDocument.py

@@ -189,6 +189,6 @@ class PDFDocument(Image, ConversionCacheMixin):
   def _setFile(self, data, precondition=None):
     try:
       del self._content_information
-    except AttributeError:
+    except (AttributeError, KeyError):
       pass
     Image._setFile(self, data, precondition)