build: more fallback to autoconf 2.69

diff --git a/m4/ax_ld_check_flag.m4 b/m4/ax_ld_check_flag.m4
index 6a7d503b87dbf176ab73de5236a81ebc1974a2bc..898168a9d6a94050ab1036db0cfa2c5a9610d62a 100644 (file)
--- a/m4/ax_ld_check_flag.m4
+++ b/m4/ax_ld_check_flag.m4
@@ -50,7 +50,7 @@
 #serial 6
 
 AC_DEFUN([AX_LDFLAGS_OPTION],[
-  AC_PREREQ([2.71])
+  AC_PREREQ([2.69])
   AC_REQUIRE([AC_PROG_SED])
 
   flag=`echo "$1" | $SED 'y% .=/+-(){}<>:*,%_______________%'`