minor comment change of dscache.c

src/dscache.c

@@ -18,6 +18,10 @@
  * documentation. */
 
 /* TODO:
+ *
+ * WARNING: most of the following todo items and design issues are no
+ * longer relevant with the new design. Here as a checklist to see if
+ * some old ideas still apply.
  *
  * - The WATCH helper will be used to signal the cache system
  *   we need to flush a given key/dbid into disk, adding this key/dbid