Improve guard so it works for no eof new line

ftplugin/ps1xml.vim

@@ -1,4 +1,5 @@
 if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'powershell') == -1
+
 " Vim filetype plugin file
 " Language:           Windows PowerShell
 " Maintainer:         Peter Provost <peter@provost.org>
@@ -30,4 +31,5 @@ endif
 let b:undo_ftplugin = "setlocal tw< cms< fo<" .
       \ " | unlet! b:browsefilter"
 
+
 endif