Make error message clearer when installed SQLite version is too old.

[Alasdair Nicol]

When an older version of sqlite is installed, the final line of the traceback is unrelated.

    raise LookupError(message)
LookupError: No installed app with label 'admin'.

If you look further up the traceback, you can see what the problem is, but this can be tricky for newer users.

    raise ImproperlyConfigured('SQLite 3.8.3 or later is required (found %s).' % Database.sqlite_version)
django.core.exceptions.ImproperlyConfigured: SQLite 3.8.3 or later is required (found 3.7.17).

I think that if we made the error message clearer it would be helpful for new users. Perhaps we could do this by checking the sqlite version in a system check, or maybe there's a better approach.

Related Stack Overflow question: ​https://stackoverflow.com/questions/55512244/no-installed-app-with-label-admin-in-empty-django-2-2-project/