今天在使用NSURLSession时候报了如下的错误：
Application 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.
解决办法如下为在info.plist文件中添加：
<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>