项目工程里，PCH 里面引入 头文件，兼容c 和 oc混编的情况

ifndef YXLiveChatKitPCH_pch

define YXLiveChatKitPCH_pch

ifdef OBJC

如果这里引入的 如果有 c 和 oc混编的 就需要加入这个 判断

endif

// Include any system framework and library headers here that should be included in all compilation units.
// You will also need to set the Prefix Header build setting of one or more of your targets to reference this file.

endif /* YXLiveChatKitPCH_pch */