Improve guard so it works for no eof new line

ftplugin/caddyfile.vim

@@ -1,4 +1,5 @@
 if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'caddyfile') == -1
+
 " Language:	    Caddyfile
 " Author:	    Josh Glendenning <josh@isobit.io>
 
@@ -23,4 +24,5 @@ else
 	let g:NERDCustomDelimiters = {'caddyfile': s:delimiters}
 endif
 unlet s:delimiters
+
 endif