plugin XEP-0277, xml_tools: restore decapsulation of XHTML content

- to avoid successive nesting of the content in <div>
    - otherwise there is a new <div> at each item modification

src/plugins/plugin_xep_0277.py

@@ -178,7 +178,11 @@ class XEP_0277(object):
                 if data_elt.uri != NS_XHTML:
                     raise failure.Failure(exceptions.DataError(_('Content of type XHTML must declare its namespace!')))
                 key = check_conflict(u'{}_xhtml'.format(elem.name))
-                data = data_elt.toXml()
+
+                # This is needed to avoid a successive encapsulation with a new <div>...</div>
+                # each time the item is modified (encapsulation is done in self.data2entry).
+                data = xml_tools.decapsulateDomishContent(data_elt)
+
                 microblog_data[key] = yield self.host.plugins["TEXT-SYNTAXES"].clean_xhtml(data)
                 microblog_data[key] = xml_tools.expandNewLinesToXHTML(microblog_data[key])
             else: