iOS 9采用https请求，运行旧工程或者未适配，会出现以下警告：
App Transport Security has blocked a cleartext HTTP (http://) resource load since it is insecure. Temporary exceptions can be configured via your app's Info.plist file.
解决办法：
1、在 Info.plist -> Open As -> Source Code
NSAppTransportSecurity
NSAllowsArbitraryLoads
图片发自简书App
2、打开 Info.plist 添加key：NSAppTransportSecurity
输入完成之后会自动变成：App Transport Security Settings
再展开，添加key：Allow Arbitrary Loads 设置为：YES
