make: change to AC_CONFIG_SRCDIR([configure.ac]) since we moved config.h.in.
diff --git a/configure.ac b/configure.ac
index 8e35d3f..ec2f280 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,7 +15,7 @@
AM_INIT_AUTOMAKE([1.10 -Wall no-define foreign])
AC_CONFIG_MACRO_DIR([m4])
-AC_CONFIG_SRCDIR([config.h.in])
+AC_CONFIG_SRCDIR([configure.ac])
# Create config.h without prefixes. Put it in the include directory so CFLAGS will have -I./include .
AC_CONFIG_HEADERS(include/config.h)
# Add prefixes and output to a unique file name which will go into the ndn-cpp include install directory.