Python example fix (#1529)

Fixed a Python example, which caused exception when running.

Signed-off-by: Akvinikym <[email protected]>

example/python/tx-example.py

@@ -169,7 +169,7 @@ def grant_admin_to_add_detail_to_userone():
     """
     tx = tx_builder.creatorAccountId("userone@domain") \
         .createdTime(current_time) \
-        .grantPermission(creator, "can_set_my_account_detail") \
+        .grantPermission(creator, iroha.Grantable_kSetMyAccountDetail) \
         .build()
 
     send_tx(tx, user1_kp)