Plinth fails to start - ModuleNotFoundError: No module named 'distutils'

This was observed on Plinth 0.25.0 on Raspberry Pi 2 and Raspberry Pi 3. This error was first observed on 22 March 2018.

Stacktrace

root@freedombox:~# plinth
Traceback (most recent call last):
  File "/usr/bin/plinth", line 21, in <module>
    plinth.__main__.main()
  File "/usr/lib/python3/dist-packages/plinth/__main__.py", line 389, in main
    configure_django()
  File "/usr/lib/python3/dist-packages/plinth/__main__.py", line 310, in configure_django
    django.setup(set_prefix=True)
  File "/usr/lib/python3/dist-packages/django/__init__.py", line 27, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/usr/lib/python3/dist-packages/django/apps/registry.py", line 85, in populate
    app_config = AppConfig.create(entry)
  File "/usr/lib/python3/dist-packages/django/apps/config.py", line 94, in create
    module = import_module(entry)
  File "/usr/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/usr/lib/python3/dist-packages/bootstrapform/__init__.py", line 1, in <module>
    from .meta import VERSION
  File "/usr/lib/python3/dist-packages/bootstrapform/meta.py", line 1, in <module>
    from distutils.version import StrictVersion
ModuleNotFoundError: No module named 'distutils'