dont crash if win32 options is cted on other platforms.

src/Windows/Avalonia.Win32/Win32Platform.cs

@@ -40,7 +40,11 @@ namespace Avalonia
     public class Win32PlatformOptions
     {
         public bool UseDeferredRendering { get; set; } = true;
-        public bool AllowEglInitialization { get; set; } = Win32Platform.WindowsVersion > new Version(6, 1);
+        
+        public bool AllowEglInitialization { get; set; } 
+            = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && 
+              Win32Platform.WindowsVersion > new Version(6, 1);
+        
         public bool? EnableMultitouch { get; set; }
         public bool OverlayPopups { get; set; }
         public bool UseWgl { get; set; }