Outdated QuerySet.iterator() documentation

[Lincoln]

The QuerySet.iterator() documentation (​https://docs.djangoproject.com/en/dev/ref/models/querysets/#iterator) says

(internally, the default iterator calls iterator() and caches the return value)

I take "the default iterator" to mean the QuerySet __iter__() method.

This does not call iterator():

​https://github.com/django/django/blob/378481165d14fea4c2a4b7717af3d7bdf9150f08/django/db/models/query.py#L417-L433

It only calls _fetch_all(), which as of this change

​https://github.com/django/django/commit/f3b7c059367a4e82bbfc7e4f0d42b10975e79f0c#diff-d58ef61559dc7af5fdf7b56fee13571a4d2948e784cd608f6afeacf3ac2fb195R1075

no longer calls iterator().

So this line in the documentation is no longer accurate. I think an appropriate fix would be to simply remove that line of quoted text from the docs.