core, plugins: fixed bad use of children instead of elements() for domish.Element instances.

src/plugins/plugin_xep_0277.py

@@ -85,8 +85,8 @@ class XEP_0277(object):
         @param item: domish.Element of microblog item
         @return: microblog data (dictionary)"""
         try:
-            entry_elt = filter(lambda x: x.name == "entry", item.children)[0]
-        except KeyError:
+            entry_elt = [child for child in item.elements() if child.name == "entry"][0]
+        except IndexError:
             warning(_('No entry element in microblog item'))
             return
         _entry = atom.Entry().import_xml(entry_elt.toXml().encode('utf-8'))