Update doc/tutorial.rst

Co-authored-by: Hayao <hayao_s@tokyo-gas.co.jp>

Author: csernazs

doc/tutorial.rst

@@ -520,7 +520,7 @@ Debugging
 ~~~~~~~~~
 
 If you having multiple requests for the server, adding the call to
-``check()`` may to debug as it will make the test failed as
+``check()`` may help to debug as it will make the test failed as
 soon as possible.
 
 .. code:: python