Improve guard so it works for no eof new line

syntax/c.vim

@@ -1,4 +1,5 @@
 if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'c/c++') == -1
+
 " Vim syntax file
 " Language:	C
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
@@ -488,4 +489,5 @@ unlet s:ft
 let &cpo = s:cpo_save
 unlet s:cpo_save
 " vim: ts=8
+
 endif