Enable build and refit for template virtual trains.

src/train_cmd.cpp

@@ -4751,6 +4751,16 @@ CommandCost CmdBuildVirtualRailVehicle(TileIndex tile, DoCommandFlag flags, uint
 		if (train == NULL) {
 			return_cmd_error(err);
 		}
+
+		if (text && text[0] == 'R') {
+			CargoID cargo = text[1];
+			if (cargo >= NUM_CARGO) return CMD_ERROR;
+			CargoID default_cargo = Engine::Get(eid)->GetDefaultCargoType();
+			if (default_cargo != cargo) {
+				CommandCost refit_res = CmdRefitVehicle(tile, flags, train->index, cargo, NULL);
+				if (!refit_res.Succeeded()) return refit_res;
+			}
+		}
 	}
 
 	return CommandCost();