app/calendar: fix typo causing void-variable error
app/calendar: fix typo causing void-variable error

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