Remove unnecessary nuget feeds

Author: kzu

src/NuGet.Config

@@ -2,10 +2,7 @@
 <configuration>
 	<packageSources>
 		<clear />
-		<add key="NuGetCI" value="https://dotnet.myget.org/F/nuget-build/api/v3/index.json" />
 		<add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />
-		<add key="Merq-CI" value="https://ci.appveyor.com/nuget/merq" />
-		<add key="Clide-CI" value="https://ci.appveyor.com/nuget/clide" />
 		<add key="NuGetVolatile" value="https://dotnet.myget.org/F/nuget-volatile/api/v3/index.json" />
 	</packageSources>
 	<disabledPackageSources>