docker compose sample

src/main/java/de/zendric/app/xpensely_server/XpenselyServerApplication.java

@@ -18,6 +18,7 @@ public class XpenselyServerApplication {
 		System.setProperty("DB_PASSWORD", dotenv.get("DB_PASSWORD"));
 		System.setProperty("DB_DEV_CONTAINER", dotenv.get("DB_DEV_CONTAINER"));
 		System.setProperty("DB_DEV_NAME", dotenv.get("DB_DEV_NAME"));
+		System.setProperty("DB_PORT", dotenv.get("DB_PORT"));
 		SpringApplication.run(XpenselyServerApplication.class, args);
 	}