RPI config: set SYS_MC_EST_GROUP

posix-configs/rpi/px4.config

@@ -4,6 +4,7 @@ param set SYS_AUTOSTART 4001
 param set MAV_BROADCAST 1
 sleep 1
 param set MAV_TYPE 2
+param set SYS_MC_EST_GROUP 0
 df_lsm9ds1_wrapper start -R 4
 #df_mpu9250_wrapper start -R 10
 #df_hmc5883_wrapper start