fix a typo introduced in r28370.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@28372 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Document.py

@@ -186,7 +186,7 @@ class ConversionCacheMixin:
     if self.isTempObject():
       if getattr(aq_base(self), 'temp_conversion_data', None) is None:
         self.temp_conversion_data = {}
-      self.temp_conversion_cache[cache_id] = (mime, aq_base(data))
+      self.temp_conversion_data[cache_id] = (mime, aq_base(data))
       return
     cache_factory = self._getCacheFactory()
     cache_duration = cache_factory.cache_duration