for LINE_MAX

Index: src/conf.c
--- src/conf.c.orig
+++ src/conf.c
@@ -23,6 +23,8 @@
  * add new directives to.  Who knows if I'm right though.
  */
 
+#include <limits.h>
+
 #include "common.h"
 #include <regex.h>
 #include "conf.h"