simulator: fix to set system and component IDs as defined in params

The simulator had hardcoded component ID and system ID (sysID was 0), ignoring what was set up in the params MAV_SYS_ID and MAV_COMP_ID. This caused an issue with multi-vehicle simulations that that rely on sysID to identify the vehicles.

Signed-off-by: Gabriel Moreno <gabrielm@cs.cmu.edu>