bug#35241: 27.0.50; Tramp can't decrypt .authinfo.gpg in Win 10

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Date: Tue, 16 Apr 2019 14:50:40 +0200
> Cc: 35241@debbugs.gnu.org, Noam Postavsky <npostavs@gmail.com>
> 
> Relative file names are not forbidden as part of exec-path. Shall we ban
> them (with an error message)? Or shall we ignore them, silently? Don't know.
> 
> I'd vote for the latter (including proper documentation).

Maybe executable-find should ignore them if default-directory is
remote?