Comment 2 for bug 1832680

Seems gtg checks network conectivity for whatever reason. Last version of flatpak manifest https://github.com/albfan/gtg/commit/380242efc5d228ccd7b7bcb03ff3105d10e3e4aa should fix that but still there's an error:

```
$ flatpak-builder --ccache --force-clean build org.gnome.Gtg.json
$ flatpak-builder --run build org.gnome.Gtg.json gtg
Traceback (most recent call last):
  File "/app/bin/gtg", line 51, in <module>
    import dbus
  File "/app/lib/python3.7/site-packages/dbus_python-1.2.8-py3.7-linux-x86_64.egg/dbus/__init__.py", line 71, in <module>
  File "/app/lib/python3.7/site-packages/dbus_python-1.2.8-py3.7-linux-x86_64.egg/dbus/types.py", line 6, in <module>
    # Iterators in Python aren't a matter of type but of protocol. A large
ModuleNotFoundError: No module named '_dbus_bindings'
```