Removing the AzureAD feed from security repo

Wilson packages are now part of aspnet myget feeds. Removing azure feed from restore sources.

Author: Praburaj

NuGet.Config

@@ -3,6 +3,5 @@
   <packageSources>
     <add key="AspNetVNext" value="https://www.myget.org/F/aspnetrelease/api/v2" />
     <add key="NuGet.org" value="https://nuget.org/api/v2/" />
-    <add key="AzureADNighty" value="http://www.myget.org/F/azureadwebstacknightly"/>
   </packageSources>
 </configuration>