加载项目时：-pie can only be used when targeting iOS 4.2 or later 错误

解决方案：

To fix this, simply select xcode project in top left. In “Deployment Info” , change Deployment target to 7.1 or later. Clean and Build. This should fix this linker issue

参考：

https://emaxtechnologie.wordpress.com/2014/11/19/ld-pie-can-only-be-used-when-targeting-ios-4-2-or-later/