Update application.properties

Fixed the environment variable used.

src/main/resources/application.properties

@@ -1,7 +1,7 @@
 spring.application.name=smart-inventory
 
 # Server CORS Configuration. 
-frontend.server.address=${ADDRESS:http://localhost:8080}
+frontend.server.address=${FRONTEND_SERVER_ADDRESS:http://localhost:8080}
 
 # Server Port Configuration.
 # The default server port is 8080.