[Issue #1] Adding #ifdef around NSURLSession-specific declarations
[Issue #1] Adding #ifdef around NSURLSession-specific declarations

AFNetworking/AFNetworkActivityLogger,Kingside/AFNetworkActivityLogger,Rich86man/AFNetworkActivityLogger,zhaihm/AFNetworkActivityLogger,ashfurrow/AFNetworkActivityLogger,podkovyrin/AFNetworkActivityLogger,adriantofan/ATNetworkActivityLoggerLumberJack,layerhq/AFNetworkActivityLogger,talk-to/AFNetworkActivityLogger,sleepio/cocoapods-afnetworkactivitylogger,sohayb/AFNetworkActivityLumberjackLogger,rbaumbach/AFNetworkActivityLogger,bespider/AFNetworkActivityLogger,pim-ltd/AFNetworkActivityLumberjackLogger