Revert "Upgrade oidc-client-hybrid.test net5"

This reverts commit 0a452fe.

Author: linianhui

1-src/web.oidc.client.hybrid/web.oidc.client.hybrid.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <AssemblyName>Web.Oidc.Client.Hybrid</AssemblyName>
     <RootNamespace>ClientSite</RootNamespace>
     <IsWebConfigTransformDisabled>true</IsWebConfigTransformDisabled>
@@ -12,8 +12,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="5.0.6" />
-    <PackageReference Include="Microsoft.AspNetCore.DataProtection.Abstractions" Version="5.0.6" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="3.1.6" />
+    <PackageReference Include="Microsoft.AspNetCore.DataProtection.Abstractions" Version="3.1.6" />
   </ItemGroup>
 
 </Project>