Re-indent the :param: comment of .

Source/Alamofire.swift

@@ -1329,7 +1329,7 @@ extension Request {
     /**
         Adds a handler to be called once the request has finished.
 
-    :param: completionHandler A closure to be executed once the request has finished. The closure takes 4 arguments: the URL request, the URL response, if one was received, the string, if one could be created from the URL response and data, and any error produced while creating the string.
+        :param: completionHandler A closure to be executed once the request has finished. The closure takes 4 arguments: the URL request, the URL response, if one was received, the string, if one could be created from the URL response and data, and any error produced while creating the string.
 
         :returns: The request.
     */