no need to check speakers type as they are always a list

Closes #3883

themis/importexport/sync.py

@@ -249,14 +249,7 @@ class SyncFromThemis(UtilityView):
                          'orateurs_en_seanceprop', 'orateurs_rapportcom',
                          'orateurs_seance_reponse_orale'):
                 if data.get(attr):
-                    speakers = data.get(attr)
-                    # check if the speakers is a list, which is not a case if
-                    # the field is of type 'Ministry or Deputy'
-                    if isinstance(speakers, list):
-                        object.speakers = list(set(object.speakers + speakers))
-                    else:
-                        if speakers not in object.speakers:
-                            object.speakers.append(speakers)
+                    object.speakers = list(set(object.speakers + data.get(attr)))
 
             if data.get('rapporteurs'):
                 object.reporters = data.get(attr)