Fix comment

Source/Alamofire.swift

@@ -400,7 +400,7 @@ public class Manager {
         /// Overrides default behavior for NSURLSessionTaskDelegate method `URLSession:willPerformHTTPRedirection:newRequest:completionHandler:`.
         public var taskDidReceiveChallenge: ((NSURLSession!, NSURLSessionTask!, NSURLAuthenticationChallenge) -> (NSURLSessionAuthChallengeDisposition, NSURLCredential!))?
 
-        /// Overrides default behavior for NSURLSessionTaskDelegate method `URLSession:task:didCompleteWithError:`.
+        /// Overrides default behavior for NSURLSessionTaskDelegate method `URLSession:session:task:needNewBodyStream:`.
         public var taskNeedNewBodyStream: ((NSURLSession!, NSURLSessionTask!) -> (NSInputStream!))?
 
         /// Overrides default behavior for NSURLSessionTaskDelegate method `URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:`.