remove unused using

Author: DewJunkie

easyWSL/RegisterNewDistro_Page.xaml.cs

@@ -7,7 +7,6 @@
 using Windows.Storage.Pickers;
 using WinRT;
 using System.Diagnostics;
-using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 using easyWslLib;