WKWebView加载网页中弹出键盘或其他H5组件时，页面自动放

    let jScript = "var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no'); document.getElementsByTagName('head')[0].appendChild(meta);"
    let js = WKUserScript.init(source: jScript, injectionTime: .atDocumentEnd, forMainFrameOnly: true)
    wkcfg.userContentController.addUserScript(js)
    let webview = WKWebView(frame: .zero, configuration: wkcfg)