patch 8.2.0017: OS/2 and MS-DOS are still mentioned

Problem:    OS/2 and MS-DOS are still mentioned, even though support was
            removed long ago.
Solution:   Update documentation. (Yegappan Lakshmanan, closes #5368)
diff --git a/runtime/vimrc_example.vim b/runtime/vimrc_example.vim
index b05793b..3017a6c 100644
--- a/runtime/vimrc_example.vim
+++ b/runtime/vimrc_example.vim
@@ -1,12 +1,12 @@
 " An example for a vimrc file.
 "
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
-" Last change:	2019 Jan 26
+" Last change:	2019 Dec 17
 "
 " To use it, copy it to
-"     for Unix and OS/2:  ~/.vimrc
+"	       for Unix:  ~/.vimrc
 "	      for Amiga:  s:.vimrc
-"  for MS-DOS and Win32:  $VIM\_vimrc
+"	 for MS-Windows:  $VIM\_vimrc
 "	    for OpenVMS:  sys$login:.vimrc
 
 " When started as "evim", evim.vim will already have done these settings, bail