doc: Make Emacs frontend description more accurate

Authored by ueno on Jul 12 2017, 9:28 PM.

Description

doc: Make Emacs frontend description more accurate

* doc/pinentry.texi (Front ends): Remove false assertions on
insecurity of Emacs, and mention allow-emacs-pinentry option of
gpg-agent.
  • Proofread-by: Marcus Brinkmann <mb@g10code.com>
  • GnuPG-bug-id: T2034