react-native-webview IOS低版本中h5长按图片弹框

在react-native-webview 源码中，ios->RNCWKWebView.m 里面:

- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation{
   [self.webView evaluateJavaScript:@"document.documentElement.style.webkitTouchCallout='none';" completionHandler:nil];
    [self.webView evaluateJavaScript:@"document.documentElement.style.webkitUserSelect='none';"completionHandler:nil];
    .....
}