remove some things in the nuget.config that were messing things up (#2368) (#2470)

Author: bbowman

nuget.config

@@ -1,20 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <config>
-    <clear />
     <add key="repositoryPath" value="packages" />
   </config>
   <packageSources>
-    <!-- When <clear /> is present, previously defined sources are ignored -->
-    <!-- Remove this tag or un-comment the nuget.org source below to restore packages from nuget.org -->
-    <!-- For more info, see https://docs.nuget.org/consume/nuget-config-file -->
-    <!-- Intentionally v2, as v3 doesn't yet support list which is used by Update-Environment.ps1 -->
     <add key="vss-package-management" value="https://www.myget.org/F/vss-package-management/api/v2" />
     <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
   </packageSources>
-  <disabledPackageSources>
-    <clear/>
-  </disabledPackageSources>
   <activePackageSource>
     <add key="All" value="(Aggregate source)" />
   </activePackageSource>