Merge branch 'hotfix/delete-activities' into 'develop'

Fix delete activities not federating

See merge request pleroma/pleroma!933

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -310,7 +310,7 @@ def unfollow(follower, followed, activity_id \\ nil, local \\ true) do
 
   def delete(%Object{data: %{"id" => id, "actor" => actor}} = object, local \\ true) do
     user = User.get_cached_by_ap_id(actor)
-    to = object.data["to"] || [] ++ object.data["cc"] || []
+    to = (object.data["to"] || []) ++ (object.data["cc"] || [])
 
     with {:ok, object, activity} <- Object.delete(object),
          data <- %{