Python not working with Flatpak install

Hi -- I just wanted to try Processing with Python so I used the Flatpak version. However it does not look like the flatpak and work with Python.

See the messages from the console. it keeps saying that it "`assumes a registry is created on port 8220`". Nothing actually happens so I do not believe this resgistry has been created.

```
$ flatpak run org.processing.processingide
$ You are running Processing revision 0265, the latest build is 0269.
$
$ created registry at port 8220
could not create registry; assume it's already created
Reference Tool 1.1.1 by Jae Hyun
could not create registry; assume it's already created
```

Is there something I need to do to activate with Python to and the Flatpak installer?

This is 64-bit ubuntu 19.04
All packages are up to date.

Reproduce the issue with `flatpak run org.processing.processingide` on the reported Ubuntu setup and review the console output around the Python activation and registry messages. Done means the Flatpak installation can activate and run Processing with Python without the registry failure.

索引モデルが issue の本文から書いたものです。