Remove unneeded macro

Headers/PCH/MobilePrefix.pch

@@ -14,7 +14,3 @@
 #else
 #define VKLog(format, ...)
 #endif
-
-#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[UIDevice currentDevice] systemVersion].floatValue >= [v floatValue])
-
-#define SYSTEM_RUNS_IOS8_OR_LATER SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"8.0")