Fix wrong-type-argument symbolp

[Rational-Curiosity]

Not only symbols can be found in key bindings.

[clemera]

Thanks, have you signed the FSF copyright papers? If not be aware that you are only allowed to contribute at max 15 lines in total to projects which they hold the copyright for.

[Rational-Curiosity]

No, i haven't. I don't know how to do it.

[clemera]

The assignment is applicable for all projects related to Emacs. It basically
transfers copyright of your submitted changes to the FSF. That way they can
enforce Copyleft.

The assignment process is very easy and can often be handled via email.

Please see the request form
if you want to do the assignment (use Emacs for the name of the program you want to contribute to).