lang/cc: fix stringp errors when loading rtags
lang/cc: fix stringp errors when loading rtags

Binary checks for rtags expect rtags-rc-binary-name and
rtags-rdm-binary-name to always be non-nil.

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