Skip filtering non-group focused annotations when deleting

The streamer will now only send the annotation id when the action is
delete. Thus we can't check if the annotation's group is currently
focused when the action is `delete`.

h/static/scripts/streamer.js

@@ -63,11 +63,14 @@ function connect($rootScope, annotationMapper, groups, session, settings) {
     }
 
     // Discard annotations that aren't from the currently focused group.
+    // Unless the action is delete, where we only get an id
     // FIXME: Have the server only send us annotations from the focused
     // group in the first place.
-    annotations = annotations.filter(function (ann) {
-      return ann.group === groups.focused().id;
-    });
+    if (action !== 'delete') {
+      annotations = annotations.filter(function (ann) {
+        return ann.group === groups.focused().id;
+      });
+    }
 
     switch (action) {
       case 'create':