为了跟新新版本的ios9版本，使用http请求时会碰到无法加载数据的情况
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.
ios9默认是https请求，这时就需要更改系统的InfoPlist文件，修改为http请求
这里先写出来，省的以后用的时候还一次一次敲代码
NSAppTransportSecurity
NSAllowsArbitraryLoads Boolean 类型改为YES