セキュアではない HTTP のダウンロードを許可する必要があるかどうか
Starting with iOS9, only HTTPS downloads are allowed by default, and plain insecure HTTP downloads are disabled. To enable them, set this property to true. When built with this setting enabled, the Xcode project will be adjusted to have the NSAppTransportSecurity dictionary added, which contains NSAllowsArbitraryLoads key.