Commit d88cdad2847726438c7d1de9fd2651c4be9243aa doesn’t build on macOS

The sed on El Capitan balks at the script constructed in autopen.sh.
This patch fixes that on macOS, can someone please test it on other platforms - don’t know if it works there as it should.
“
diff --git a/autogen.sh b/autogen.sh
index f6bfde6..e6d7ef4 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -224,7 +224,8 @@ do_git=
   ## Create nt/gnulib.mk if it doesn't exist, as autoreconf will need it.
   if test ! -f nt/gnulib.mk; then
       echo 'Inferring nt/gnulib.mk from lib/gnulib.mk ...'
-      metascript='/^[^#]/s|^.*$|/^## begin  *gnulib module &/,/^## end  *gnulib module &/c ## gnulib module & removed|'
+      metascript='/^[^#]/s|^.*$|/^## begin  *gnulib module &/,/^## end  *gnulib module &/c\
+ ## gnulib module & removed|'
       script=`sed "$metascript" nt/gnulib-modules-to-delete.cfg` || exit
       sed "$script" lib/gnulib.mk > nt/gnulib.mk || exit
   fi
“

to ./configure it quicker, you need to add --without-makeinfo (default makeinfo is 4.8, >4.13 is required) and --with-gnutls=no if you don’t have gnutls installed

See also:
https://lists.gnu.org/archive/html/emacs-devel/2017-01/msg00048.html