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configure.ac:448: warning: The macro `AC_TYPE_SIGNAL' is obsolete.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>

diff --git a/configure.ac b/configure.ac
index 141acc6cad95cb4acffad61f7059b20496717929..0f667dcaf4f0ab48a3b6541fd546be6cfe4ea9a0 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])