Reset overall lifetime profit to 0 when renewing vehicle.

src/vehicle_base.h

@@ -669,6 +669,7 @@ public:
 
 		this->profit_this_year = src->profit_this_year;
 		this->profit_last_year = src->profit_last_year;
+		this->profit_lifetime = -this->profit_this_year;
 	}