vim: add commentstring to ftplugin

integration/vim/ft-emboss/ftplugin/emboss.vim

diff --git a/integration/vim/ft-emboss/ftplugin/emboss.vim b/integration/vim/ft-emboss/ftplugin/emboss.vim
index 7880796..b829a8e 100644
--- a/integration/vim/ft-emboss/ftplugin/emboss.vim
+++ b/integration/vim/ft-emboss/ftplugin/emboss.vim
@@ -17,10 +17,11 @@
 if exists('b:did_ftplugin')
   finish
 endif
-let b:did_ftplugin = 1
 
-let b:undo_ftplugin = 'setlocal comments< formatoptions< iskeyword<'
+let b:did_ftplugin = 1
+let b:undo_ftplugin = 'setlocal comments< commentstring< formatoptions< iskeyword<'
 
 setlocal formatoptions-=t
 setlocal comments=b:--,:#
 setlocal iskeyword+=$
+setlocal commentstring=# %s