fix(): simplify logic for failed URLs error code on iOS6/7

@@ -194,7 +194,7 @@
 
                     BOOL shouldBeFailedURLAlliOSVersion = (error.code != NSURLErrorNotConnectedToInternet && error.code != NSURLErrorCancelled && error.code != NSURLErrorTimedOut);
                     BOOL shouldBeFailedURLiOS7 = (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_6_1 && error.code != NSURLErrorInternationalRoamingOff && error.code != NSURLErrorCallIsActive && error.code != NSURLErrorDataNotAllowed);
-                    if (shouldBeFailedURLAlliOSVersion && (NSFoundationVersionNumber <= NSFoundationVersionNumber_iOS_6_1 || shouldBeFailedURLiOS7)) {
+                    if (shouldBeFailedURLAlliOSVersion || shouldBeFailedURLiOS7) {
                         @synchronized (self.failedURLs) {
                             [self.failedURLs addObject:url];
                         }