bug#39802: (info "(emacs) Init Rebinding") needs to say it is impossible to unbind local keys

[積丹尼 Dan Jacobson]

If

  C-. runs the command flyspell-auto-correct-word (found in
  flyspell-mode-map), which is an interactive compiled Lisp function in
 ‘flyspell.el’.

  It is bound to C-., C-M-i.

And the user wants to unbind it, well,
(info "(emacs) Init Rebinding")
won't break the bad news to him that it is just not possible.