build: fix build for automake 1.12

automake-1.12 complains about missing AC_PROG_AR so add it.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/configure.ac b/configure.ac
index f5d2af0..bcb6be8 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -17,6 +17,7 @@ AC_USE_SYSTEM_EXTENSIONS
 AC_PROG_CC
 AC_PROG_CC_C99
 AM_PROG_CC_C_O
+AM_PROG_AR
 
 LT_PREREQ(2.2)
 LT_INIT