Order Manager returns a ack with MSA-1=AE when the PATIENT group is missing in OML^O* whereas this group is set as RE in TF

When parsing the OML messages for LAB-1 and LAB-2 transactions, the simulator sends an application error if the PATIENT group is missing
In the TF (Rev 3.0) this group is "Required or empty"
We need to change the condition in the OrderReceiver class to remove this wrong requirement