missing: don't bother checking for AM_CONFIG_HEADER: it is gone now

* missing (autoheader*): Do not look for AM_CONFIG_HEADER when
grepping configure.ac: it is not supported anymore (has been in
fact deleted in commit v1.12-15-gd2ca168 of 2012-04-27, "m4: delete
several obsolete macros").

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/lib/missing b/lib/missing
index 9a5564823de4c47d7825a85adea87328123cb6ff..890514460cd9590ede2f681c6f6380826397eb22 100755 (executable)
--- a/lib/missing
+++ b/lib/missing
@@ -160,7 +160,7 @@ WARNING: '$1' is $msg.  You should only need it if
          you modified 'acconfig.h' or '${configure_ac}'.  You might want
          to install the Autoconf and GNU m4 packages.  Grab them
          from any GNU archive site."
-    files=`sed -n 's/^[ ]*A[CM]_CONFIG_HEADER(\([^)]*\)).*/\1/p' ${configure_ac}`
+    files=`sed -n 's/^[ ]*AC_CONFIG_HEADER(\([^)]*\)).*/\1/p' ${configure_ac}`
     test -z "$files" && files="config.h"
     touch_files=
     for f in $files; do