[Issue #1379] Adding missing code macros for iOS 6 compatibility in U…

…IAlertView category

UIKit+AFNetworking/UIAlertView+AFNetworking.h

@@ -45,8 +45,10 @@
  @param task The session task.
  @param delegate The alert view delegate.
  */
+#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 70000
 + (void)showAlertViewForTaskWithErrorOnCompletion:(NSURLSessionTask *)task
                                          delegate:(id)delegate;
+#endif
 
 /**
  Shows an alert view with the error of the specified session task, if any, with a custom cancel button title and other button titles.
@@ -56,10 +58,12 @@
  @param cancelButtonTitle The title of the cancel button or nil if there is no cancel button. Using this argument is equivalent to setting the cancel button index to the value returned by invoking addButtonWithTitle: specifying this title.
  @param otherButtonTitles The title of another button. Using this argument is equivalent to invoking addButtonWithTitle: with this title to add more buttons. Too many buttons can cause the alert view to scroll. For guidelines on the best ways to use an alert in an app, see "Temporary Views". Titles of additional buttons to add to the receiver, terminated with `nil`.
  */
+#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 70000
 + (void)showAlertViewForTaskWithErrorOnCompletion:(NSURLSessionTask *)task
                                          delegate:(id)delegate
                                 cancelButtonTitle:(NSString *)cancelButtonTitle
                                 otherButtonTitles:(NSString *)otherButtonTitles, ... NS_REQUIRES_NIL_TERMINATION;
+#endif
 
 ///------------------------------------------
 /// @name Showing Alert for Request Operation