build: fix autoconf multicast check on OpenBSD

Fix the "BSD struct ip_mreq hack" autoconf test to work with OpenBSD.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

diff --git a/configure.ac b/configure.ac
index 7764df7173521e428d576bef1f4554279c10a76d..4cc940061f0e590118a7f774c5b485ac264fe1cf 100755 (executable)
--- a/configure.ac
+++ b/configure.ac
@@ -957,7 +957,7 @@ AC_CHECK_MEMBERS([struct ip_mreqn.imr_ifindex], [], [], QUAGGA_INCLUDES)
 AC_MSG_CHECKING([for BSD struct ip_mreq hack])
 AC_TRY_COMPILE([#ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
-#endif],[#if (defined(__FreeBSD__) && ((__FreeBSD_version >= 500022 && __FreeBSD_version < 700000) || (__FreeBSD_version < 500000 && __FreeBSD_version >= 440000))) || (defined(__NetBSD__) && defined(__NetBSD_Version__) && __NetBSD_Version__ >= 106010000)
+#endif],[#if (defined(__FreeBSD__) && ((__FreeBSD_version >= 500022 && __FreeBSD_version < 700000) || (__FreeBSD_version < 500000 && __FreeBSD_version >= 440000))) || (defined(__NetBSD__) && defined(__NetBSD_Version__) && __NetBSD_Version__ >= 106010000) || defined(__OpenBSD__)
   return (0);
 #else
   #error No support for BSD struct ip_mreq hack detected