correct duplicate docstring on different functions

flask_jwt/__init__.py

@@ -292,7 +292,7 @@ def auth_response_handler(self, callback):
         return callback
 
     def auth_request_handler(self, callback):
-        """Specifies the authentication response handler function.
+        """Specifies the authentication request handler function.
 
         :param callable callback: the auth request handler function