configure.ac: Remove unused AC_TYPE_SIGNAL macro

Recent autoconf warns:
configure.ac:448: warning: The macro `AC_TYPE_SIGNAL' is obsolete.

And it turns out that we do not actually use RETSIGTYPE.
Additionally, there is no reason to do so since as the
autoconf documentation says:
"These days, it is portable to assume C89, and that signal
handlers return void, without needing to use this macro or
RETSIGTYPE."

Change-Id: I7da7c2d7d34c7e5efd52d448646b4398a1005e77
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Message-Id: <20231128103740.61160-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27572.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit be05b590e8d5edebd8e35d97af34b0ba7e5350e6)

diff --git a/configure.ac b/configure.ac
index 052fe3f907a633b01e63aa2e0aeba326518a4c34..5f9e0171a7abfcb136e517adfe43594c5c55dc3d 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -445,7 +445,6 @@ AC_TYPE_OFF_T
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_TYPE_UID_T
-AC_TYPE_SIGNAL
 AX_TYPE_SOCKLEN_T
 AC_CHECK_SIZEOF([unsigned int])
 AC_CHECK_SIZEOF([unsigned long])