Don't remove from queue until completion handler is called

Multiplatform/Shared/Article/WebViewProvider.swift

@@ -113,8 +113,8 @@ class WebViewProviderDequeueOperation: MainThreadOperation {
 	func run() {
 		if let webView = queue.lastObject as? PreloadedWebView {
 			webView.ready { preloadedWebView in
-				self.queue.removeLastObject()
 				self.completion(preloadedWebView)
+				self.queue.remove(webView)
 			}
 			self.operationDelegate?.operationDidComplete(self)
 			return