Improve Alarm_updateOpenOrderSimulation: optimize params, Minimise transaction size and reduce priority.

params can be None so for simplicity set it to {}

Conflicts:
	bt5/erp5_open_trade/bt/revision

Minimise transaction size.

Conflicts:
	bt5/erp5_open_trade/bt/revision

Lower priority.

Alarm can generate a lot of activities, so run them less often then critical
ones.

Conflicts:
	bt5/erp5_open_trade/bt/revision