Remove trailing whitespace

Ix.NET/Source/System.Linq.Async/System/Linq/AsyncEnumerable.AsyncOverloads.cs

@@ -1,6 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT License.
-// See the LICENSE file in the project root for more information. 
+// See the LICENSE file in the project root for more information.
 
 using System.Collections.Generic;
 using System.Threading;