fix

ShortagePush/Dockerfile

-FROM microsoft/dotnet:2.1-runtime-alpine AS base
+FROM mcr.microsoft.com/dotnet/core/aspnet:2.1-stretch-slim AS base
 WORKDIR /app
 RUN /bin/cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime && echo 'Asia/Shanghai' >/etc/timezone
 
-FROM microsoft/dotnet:2.1-sdk-alpine AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:2.1-stretch AS build
 WORKDIR /src
 COPY ShortagePush/ShortagePush.csproj ShortagePush/
 COPY AutoTurnOver.Services/AutoTurnOver.Services.csproj AutoTurnOver.Services/