* color.c (color_update): Add check for whether the file even exists
	  before we try to run the magic check on it.  Fixes error messages to stderr
	  when reading in files that don't exist, reported by Mike Frysinger.




git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@4540 35c25a1d-7b9e-4130-9fde-d3aeb78583b8