bug#39540: when emacsclient invoked messages left in minibuffer should be swept

[積丹尼 Dan Jacobson]

If
"Directory has changed on disk; type g to update Dired"
is sitting in the minibuffer when one does
$ emacsclient -n some_file.txt
that message should be cleared. Instead it is left sitting there,
even though we are not looking at a dired buffer anymore.
It should be just like we did C-x C-f...
emacs-version "26.3"