[py3] Force evaluation of dict's items() before modifying the dict

cubicweb_seda/entities/profile_generation.py

@@ -306,7 +306,7 @@ class SEDA2ExportAdapter(EntityAdapter):
         attributes = attributes or {}
         tag = self.qname(tag)
         documentation = attributes.pop('documentation', None)
-        for attr, value in attributes.items():
+        for attr, value in list(attributes.items()):
             newattr = substitute_xml_prefix(attr, self.namespaces)
             attributes[newattr] = value
             if newattr != attr: