Revert change to NuGet.config

Author: cormacpayne

NuGet.config

@@ -6,9 +6,4 @@
     <add key="dotnet-core" value="https://dotnet.myget.org/F/dotnet-core/api/v3/index.json" />
     <add key="powershell-core" value="https://powershell.myget.org/F/powershell-core/api/v3/index.json" />
   </packageSources>
-  <disabledPackageSources>
-    <add key="local-feed" value="true" />
-    <add key="dotnet-core" value="true" />
-    <add key="powershell-core" value="true" />
-  </disabledPackageSources>
 </configuration>