Switch to GenHTTP version 2.8.1 (#5515)

frameworks/CSharp/genhttp/Benchmarks/Benchmarks.csproj

@@ -18,8 +18,8 @@
   </PropertyGroup>
     
   <ItemGroup>
-    <PackageReference Include="GenHTTP.Core" Version="2.8.0" />
-    <PackageReference Include="GenHTTP.Modules.Webservices" Version="2.8.0" />
+    <PackageReference Include="GenHTTP.Core" Version="2.8.1" />
+    <PackageReference Include="GenHTTP.Modules.Webservices" Version="2.8.1" />
   </ItemGroup>
   
 </Project>