Update a_default 'altstep' to skip unsolicited secured CAM messages

ttcn/GeoNetworking/LibItsGeoNetworking_Functions.ttcn

@@ -1135,6 +1135,15 @@ module LibItsGeoNetworking_Functions {
                ) {
                 repeat;
             }
+            [] geoNetworkingPort.receive(
+                mw_geoNwInd(
+                    mw_geoNwSecPdu(
+                        mdw_secureMessageCAMs_dummy, 
+                        ?
+            ))) {
+                // Skip CAM messages
+                repeat;
+            }
             [] geoNetworkingPort.receive {
                 log("*** a_default: WARNING: Received an unexpected message ***");
                 repeat;