mtpd: remove a TODO which was already done two months ago.
diff --git a/l2tp.c b/l2tp.c
index 10fc045..8d46e1b 100644
--- a/l2tp.c
+++ b/l2tp.c
@@ -33,8 +33,6 @@
 
 #include "mtpd.h"
 
-/* TODO: Support secrets. */
-
 /* To avoid unnecessary endianness conversions, tunnels, sessions, attributes,
  * and values are all accessed in network order. */