Fix build warnings: unused variable and obsolete dpiAware settings.

v2rayN/v2rayN/Handler/SysProxyHandle.cs

@@ -20,7 +20,6 @@ namespace v2rayN.Handler
         //  <proxy-server><CR-LF>
         //  <bypass-list><CR-LF>
         //  <pac-url>
-        private static SysproxyConfig? _userSettings = null;
 
         private enum RET_ERRORS : int
         {

v2rayN/v2rayUpgrade/Program.cs

@@ -13,6 +13,7 @@ namespace v2rayUpgrade
         {
             Application.EnableVisualStyles();
             Application.SetHighDpiMode(HighDpiMode.SystemAware);
+            Application.SetHighDpiMode(HighDpiMode.PerMonitorV2);
             Application.SetCompatibleTextRenderingDefault(false);
             Application.Run(new MainForm(args));
         }

v2rayN/v2rayUpgrade/app.manifest

@@ -2,8 +2,6 @@
 <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
   <asmv3:application>
     <asmv3:windowsSettings>
-      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware>
-      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2</dpiAwareness>
     </asmv3:windowsSettings>
   </asmv3:application>
 </assembly>