Delete app.config file that isn't consumed anywhere

src/VisualStudio/Core/Def/ServicesVisualStudio.csproj

@@ -762,7 +762,6 @@
     <Compile Include="Implementation\ProjectSystem\MetadataReferences\VisualStudioMetadataReferenceManager.Factory.cs" />
   </ItemGroup>
   <ItemGroup>
-    <None Include="app.config" />
     <None Include="project.json" />
     <PublicAPI Include="PublicAPI.Shipped.txt" />
     <PublicAPI Include="PublicAPI.Unshipped.txt" />

src/VisualStudio/Core/Def/app.config

-<?xml version="1.0" encoding="utf-8" ?>
-<configuration>
-  <runtime>
-    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
-      <dependentAssembly>
-        <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral"/>
-        <bindingRedirect oldVersion="1.0.0.0-1.65535.65535.65535" newVersion="1.1.37.0"/>
-      </dependentAssembly>
-    </assemblyBinding>
-  </runtime>
-</configuration>