[v2] Only call EnableSizable for normal windows

Frameless windows are always not resizable per default and
the resizing for those will be initiated by the frontend see
processMessage.

If EnableSizable is enabled for frameless windows, a small white
titlebar will be shown.

Fix #1049

v2/internal/frontend/desktop/windows/window.go

@@ -55,12 +55,17 @@ func NewWindow(parent winc.Controller, appoptions *options.App) *Window {
 
 	result.SetSize(appoptions.Width, appoptions.Height)
 	result.SetText(appoptions.Title)
-	if appoptions.Frameless == false && !appoptions.Fullscreen {
-		result.EnableMaxButton(!appoptions.DisableResize)
-		result.SetMinSize(appoptions.MinWidth, appoptions.MinHeight)
-		result.SetMaxSize(appoptions.MaxWidth, appoptions.MaxHeight)
+	if appoptions.Frameless == false {
+		if !appoptions.Fullscreen {
+			result.EnableMaxButton(!appoptions.DisableResize)
+			result.SetMinSize(appoptions.MinWidth, appoptions.MinHeight)
+			result.SetMaxSize(appoptions.MaxWidth, appoptions.MaxHeight)
+		}
+		// Only call EnableSizable for normal windows, frameless windows are always not resizable per default and
+		// the resizing for those will be initiated by the frontend see processMessage.
+		// If EnableSizable is enabled for frameless windows, a small white titlebar will be shown.
+		result.EnableSizable(!appoptions.DisableResize)
 	}
-	result.EnableSizable(!appoptions.DisableResize)
 
 	if appoptions.Windows != nil {
 		if appoptions.Windows.WindowIsTranslucent {