Merge pull request #221 from pqarmitage/update_configure

Update configure in line with configure.in - request #1

configure

@@ -3755,6 +3755,21 @@ fi
 
 done
 
+for ac_header in libnfnetlink/libnfnetlink.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "libnfnetlink/libnfnetlink.h" "ac_cv_header_libnfnetlink_libnfnetlink_h" "$ac_includes_default"
+if test "x$ac_cv_header_libnfnetlink_libnfnetlink_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBNFNETLINK_LIBNFNETLINK_H 1
+_ACEOF
+
+else
+  as_fn_error $? "
+  !!! Please install libnfnetlink headers.              !!!" "$LINENO" 5
+fi
+
+done
+
 ac_fn_c_check_decl "$LINENO" "ETHERTYPE_IPV6" "ac_cv_have_decl_ETHERTYPE_IPV6" "#include <net/ethernet.h>
 "
 if test "x$ac_cv_have_decl_ETHERTYPE_IPV6" = xyes; then :