Silencing Emacs Warning about Fira

[Lorenzo Isella <lorenzo.isella@gmail.com>]

Dear All,
I run emacs on Debian stable. I use it both for writing code and to
compose emails (I use mutt which invokes emacs when I want to reply
and/or write an email).
So far so good, but I have recently added a new part to my .emacs file
(see below).


#########################################################################
;; (require 'fira-code-mode)
;; (custom-set-variable 'fira-code-mode-disabled-ligatures '("[]" "#{" "#(" "#_" "#_(" "x")) ;; List of ligatures to turn off

;; ;; Enable fira-code-mode automatically for programming major modes
;; (add-hook 'prog-mode-hook 'fira-code-mode)
;; ;; Or, you can use the global mode instead of adding a hook:
;; (global-fira-code-mode)


;; (require 'fira-code-mode)

;; install use-package from melpa and also fira

;; See https://github.com/jming422/fira-code-mode

(use-package fira-code-mode
   :custom (fira-code-mode-disabled-ligatures '("[]" "www" "<-" "#{" "#(" "#_" "#_(" "x")) ;; List of ligatures to turn off
   :hook prog-mode) ;; Enables fira-code-mode automatically for programming major modes

;; (set-frame-font "FiraCode-Regular-Symbol")

##############################################################

Once again, no issues here and I have some nice ligatures as intended.
However, when I try to reply to an email via mutt and emacs is
invoked, I always get this warning

#################################################################
Warning (fira-code-ligatures): fira-code-mode probably won't work for non-graphical displays!               
###################################################################

and the buffer is split. It is not the end of the world, but it is
just annoying. Since everything then works fine when I compose and
send the email, how can I silence/get rid of this warning?
Many thanks!

Lorenzo