Put smarter dag max rank increment 2048. 0 affect a lot of troubles.

Change-Id: Ifdae0910847287a7fd67c9f3c0999149f288845c

Author: Juha Heiskanen

source/6LoWPAN/ws/ws_bbr_api.c

@@ -55,7 +55,7 @@ static void ws_bbr_rpl_root_activate(uint8_t *dodag_prefix, uint8_t *dodag_id)
         .objective_code_point = 1, // MRHOF algorithm used
         .authentication = 0,
         .path_control_size = 0,
-        .dag_max_rank_increase = 0,
+        .dag_max_rank_increase = 2048,
         .min_hop_rank_increase = 128,
         // DIO configuration
         .dio_interval_min = WS_RPL_DIO_IMIN,