remove old feeds

Ix.NET/Integration/NuGet.Config

@@ -1,11 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <packageSources>
-    <clear />
-    <add key="myget.org dotnet-core" value="https://dotnet.myget.org/F/dotnet-core/api/v3/index.json" />
-    <add key="myget.org rxnet" value="https://www.myget.org/F/rxnet/api/v3/index.json" />
-    <add key="Build Packages" value="https://www.myget.org/F/c037199d-41df-4567-b966-25ff65324688/api/v3/index.json" />
-    <add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />        
+    <add key="dotnet-public" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json" />
+    <add key="RxNet CI" value="https://pkgs.dev.azure.com/dotnet/Rx.NET/_packaging/RxNet/nuget/v3/index.json" />    
   </packageSources>
   <config>
     <!--<add key="repositoryPath" value="..\..\packages" />-->