Refactor gnutls-algorithm-priority
Refactor gnutls-algorithm-priority

And prevent void-variable error if gnutls is, for some reason,
unavailable or libgnutls-version isn't a numeric.

hlissner/doom-emacs,UndeadKernel/emacs_doom,hlissner/.emacs.d,UndeadKernel/emacs_doom,UndeadKernel/emacs_doom,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/.emacs.d,UndeadKernel/emacs_doom,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/doom-emacs,hlissner/.emacs.d,UndeadKernel/emacs_doom,UndeadKernel/emacs_doom,hlissner/.emacs.d,hlissner/doom-emacs,UndeadKernel/emacs_doom,hlissner/doom-emacs