bluetooth: mesh: set subscription address on response

This fixes an issue where a subsequent Config Model Subscription Add
message with the same virtual address UUID would result in a Config
Model Subscription Status message with the Address field incorrectly set
to 0.

Signed-off-by: Pavel Vasilyev <pavel.vasilyev@nordicsemi.no>

Author: PavelVPV

subsys/bluetooth/mesh/cfg_srv.c

@@ -1429,6 +1429,7 @@ static int mod_sub_va_add(const struct bt_mesh_model *model,
 		/* Tried to add existing subscription */
 		status = STATUS_SUCCESS;
 		(void)bt_mesh_va_del(va->uuid);
+		sub_addr = va->addr;
 		goto send_status;
 	}