runtime(manpager): avoid readonly prompt

fixes: #15103
closes: #15106

Signed-off-by: Enno <Konfekt@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/plugin/manpager.vim b/runtime/plugin/manpager.vim
index 076aca5..6ed6030 100644
--- a/runtime/plugin/manpager.vim
+++ b/runtime/plugin/manpager.vim
@@ -1,6 +1,6 @@
 " Vim plugin for using Vim as manpager.
 " Maintainer: Enno Nagel <ennonagel+vim@gmail.com>
-" Last Change: 2022 Oct 17
+" Last Change: 2024 Jul 03
 
 if exists('g:loaded_manpager_plugin')
   finish
@@ -20,9 +20,6 @@
   endif
   syntax on
 
-  " Make this an unlisted, readonly scratch buffer
-  setlocal buftype=nofile noswapfile bufhidden=hide nobuflisted readonly
-
   " Ensure text width matches window width
   setlocal foldcolumn& nofoldenable nonumber norelativenumber
 
@@ -45,6 +42,9 @@
   " Finished preprocessing the buffer, prevent any further modifications
   setlocal nomodified nomodifiable
 
+  " Make this an unlisted, readonly scratch buffer
+  setlocal buftype=nofile noswapfile bufhidden=hide nobuflisted readonly
+
   " Set filetype to man even if ftplugin is disabled
   setlocal filetype=man
   runtime ftplugin/man.vim