change project type

Dockerfile

@@ -1,9 +1,7 @@
 #See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.
 
-FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
+FROM mcr.microsoft.com/dotnet/core/runtime:3.1-buster-slim AS base
 WORKDIR /app
-EXPOSE 80
-EXPOSE 443
 
 FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
 WORKDIR /src