Another build fix.

Benchmarks/Benchmarks.csproj

@@ -12,14 +12,6 @@
     <RootNamespace>MirrorSharp.Benchmarks</RootNamespace>
   </PropertyGroup>
   
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
-    <LangVersion>7.1</LangVersion>
-  </PropertyGroup>
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
-    <LangVersion>7.1</LangVersion>
-  </PropertyGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\Common\Common.csproj" />
     <ProjectReference Include="..\Testing\Testing.csproj" />