avy-escape-chars contradiction

[psionic-k]

I've been replacing some bindings and found a way to make a funny error message. First set avy-escape-chars

(use-package avy
  :custom
  (avy-escape-chars '(?\e ?\M-g)))

Now pressing C-g gives the error message:

No such candidate: ^G, hit ‘C-g’ to quit.

Using the last character of the avy-escape-chars variable to print the error would also fix the error

As a more total fix, it may be acceptable to look at keyboard-quit binding and add it to this list, then use the last character of the list to print the error message. If a user has rebound C-g in time for discovery, it will default to pretty good behavior.

Easy to fix, just want to discuss before I PR this