bug#38457: 27.0.50; dabbrev-expand regression due to message change

[Drew Adams]

> There's no need for something as drastic as C-g.  You could instead
> press left-arrow, for example, or some other similarly harmless key.

Yes.  It might be good to (somewhere) point
this out in the Emacs manual.  Some aspects
of (useful) minibuffer interaction might not
be obvious.

> No one argues against fixing this annoyance.  But the fix should not
> cause more problems than the problem it fixes, and it should not
> change behavior in incompatible ways. In addition, we want to start
> the Emacs 27 release cycle soon, so we don't want invasive changes in
> infrastructure used all over the place.

+1