Remove unused CONFIG_SECONDS.

Bug: https://code.google.com/p/android/issues/detail?id=65951
Change-Id: I8ae7057c68e16618de6dd06cf052426c6cad8a3d
diff --git a/libc/dns/resolv/res_cache.c b/libc/dns/resolv/res_cache.c
index 573fcbe..5a78450 100644
--- a/libc/dns/resolv/res_cache.c
+++ b/libc/dns/resolv/res_cache.c
@@ -104,10 +104,6 @@
  */
 #define  CONFIG_ENV  "BIONIC_DNSCACHE"
 
-/* entries older than CONFIG_SECONDS seconds are always discarded.
- */
-#define  CONFIG_SECONDS    (60*10)    /* 10 minutes */
-
 /* default number of entries kept in the cache. This value has been
  * determined by browsing through various sites and counting the number
  * of corresponding requests. Keep in mind that our framework is currently