THRIFT-4990 Upgrade to .NET Core 3.1 (LTS)
Client: netstd
Patch: Jens Geyer

This closes #1961
diff --git a/tutorial/netstd/Server/Server.csproj b/tutorial/netstd/Server/Server.csproj
index 454f332..b3ff516 100644
--- a/tutorial/netstd/Server/Server.csproj
+++ b/tutorial/netstd/Server/Server.csproj
@@ -19,7 +19,7 @@
   -->
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <AssemblyName>Server</AssemblyName>
     <PackageId>Server</PackageId>
     <OutputType>Exe</OutputType>
@@ -38,7 +38,7 @@
     <PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
     <PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="2.2.1" />
     <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="2.2.0" />
-    <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="2.2.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="3.1.0" />
   </ItemGroup>
 
 </Project>