[configure] remote support for AIX, it conflicts on newer autoconf

AC_AIX and AC_GNU_SOURCE conflict > autoconf 2.53 or so,
but the replacement AC_USE_SYSTEM_EXTENSIONS isn't available
until later versions.  So either we narrow the supported
autconf version range, or disable AIX (if it has any effect),
or determin that AC_AIX doesn't do anything useful anyhow.

diff --git a/configure.ac b/configure.ac
index 0b8724ee7b1d6123f4e6dc098c3910d96653a057..56fa55e0d2a7c0746b9ed7763df67b69e676f13d 100755 (executable)
--- a/configure.ac
+++ b/configure.ac
@@ -167,7 +167,6 @@ AC_CACHE_CHECK([if ${MAKE-make} is GNU make], [quagga_cv_gnu_make],
 dnl -----------------
 dnl System extensions
 dnl -----------------
-AC_AIX
 AC_GNU_SOURCE
 
 dnl -------