Add reference dependency

Author: JamesNK

src/Http/Routing/src/Microsoft.AspNetCore.Routing.csproj

@@ -46,6 +46,7 @@
     <Reference Include="Microsoft.AspNetCore.Http.Features" />
     <Reference Include="Microsoft.AspNetCore.Http.Abstractions" />
     <Reference Include="Microsoft.AspNetCore.Routing.Abstractions" />
+    <Reference Include="Microsoft.Extensions.Diagnostics" />
     <Reference Include="Microsoft.Extensions.Features" />
     <Reference Include="Microsoft.Extensions.ObjectPool" />
     <Reference Include="Microsoft.Extensions.Options" />