update to autocomplete syntax

wagtailvideos/models.py

@@ -94,9 +94,9 @@ class AbstractVideo(CollectionMember, index.Indexed, models.Model):
     objects = VideoQuerySet.as_manager()
 
     search_fields = list(CollectionMember.search_fields) + [
-        index.SearchField('title', partial_match=True, boost=10),
+        index.AutocompleteField('title', boost=10),
         index.RelatedFields('tags', [
-            index.SearchField('name', partial_match=True, boost=10),
+            index.AutocompleteField('name', boost=10),
         ]),
         index.FilterField('uploaded_by_user'),
     ]