utils: smpp_mirror: set registered_delivery field in SMPP SUBMIT_SM

To test delivery reports using this utility.

Change-Id: I0e477407531fdd4d906e53c9b5a48a79a239966f
diff --git a/src/utils/smpp_mirror.c b/src/utils/smpp_mirror.c
index 95df5f2..ec28f0a 100644
--- a/src/utils/smpp_mirror.c
+++ b/src/utils/smpp_mirror.c
@@ -130,6 +130,7 @@
 			 sizeof(deliver.destination_addr)));
 
 	submit.esm_class = deliver.esm_class;
+	submit.registered_delivery = deliver.registered_delivery;
 	submit.protocol_id = deliver.protocol_id;
 	submit.priority_flag = deliver.priority_flag;
 	memcpy(submit.schedule_delivery_time, deliver.schedule_delivery_time,