Improve guard so it works for no eof new line

autoload/cargo.vim

@@ -1,4 +1,5 @@
 if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'rust') == -1
+
 function! cargo#Load() 
     " Utility call to get this script loaded, for debugging
 endfunction
@@ -114,4 +115,5 @@ function! cargo#runtarget(args)
 endfunction
 
 " vim: set et sw=4 sts=4 ts=8:
+
 endif