fix: icons on thumbnails could sometimes be incorrect

example use-case: show a Finder window, and middle-click it. The next thumbnail under the mouse will not show its purple quit icon

src/ui/main-window/ThumbnailView.swift

@@ -132,7 +132,7 @@ class ThumbnailView: FlippedView {
 
     func showOrHideWindowControls(_ shouldShowWindowControls: Bool) {
         let shouldShow = shouldShowWindowControls && !Preferences.hideColoredCircles && !Appearance.hideThumbnails
-        if Preferences.appearanceStyle == .thumbnails, isShowingWindowControls != shouldShow {
+        if Preferences.appearanceStyle == .thumbnails {
             isShowingWindowControls = shouldShow
             for icon in windowControlIcons {
                 icon.isHidden = !shouldShow