Improve guard so it works for no eof new line

indent/dune.vim

@@ -1,4 +1,5 @@
 if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'ocaml') == -1
+
 " Vim indent file
 " Language: dune
 
@@ -9,4 +10,5 @@ let b:did_indent = 1
 
 " dune format-dune-file uses 1 space to indent
 set softtabstop=1 shiftwidth=1 expandtab
+
 endif