Update runtime files
diff --git a/runtime/indent/config.vim b/runtime/indent/config.vim
index c987a78..b840b1e 100644
--- a/runtime/indent/config.vim
+++ b/runtime/indent/config.vim
@@ -1,9 +1,10 @@
" Vim indent file
-" Language: Autoconf configure.{ac,in} file
-" Previous Maintainer: Nikolai Weibull <now@bitwi.se>
-" Latest Revision: 2006-12-20
-" TODO: how about nested [()]'s in one line
-" what's wrong with '\\\@!'?
+" Language: Autoconf configure.{ac,in} file
+" Maintainer: Doug Kearns <dougkearns@gmail.com>
+" Previous Maintainer: Nikolai Weibull <now@bitwi.se>
+" Last Change: 24 Sep 2021
+
+" TODO: how about nested [()]'s in one line what's wrong with '\\\@!'?
" Only load this indent file when no other was loaded.
if exists("b:did_indent")
@@ -16,6 +17,8 @@
setlocal indentkeys=!^F,o,O,=then,=do,=else,=elif,=esac,=fi,=fin,=fil,=done
setlocal nosmartindent
+let b:undo_indent = "setl inde< indk< si<"
+
" Only define the function once.
if exists("*GetConfigIndent")
finish