app.config is not necessary, nuget is just being dumb

(cherry picked from commit 4c56dc2)

Author: nul800sebastiaan

src/Umbraco.Deploy.Contrib.Tests/Umbraco.Deploy.Contrib.Tests.csproj

@@ -271,7 +271,6 @@
     <Compile Include="TestHelpers\TestFileTypeCollection.cs" />
   </ItemGroup>
   <ItemGroup>
-    <None Include="app.config" />
     <None Include="packages.config" />
   </ItemGroup>
   <ItemGroup>