The Guided Decision Table lock does not work when one of the users is in another tab (in the GDT Editor).

Steps do reproduce:

• Login with the `user1`;
• Login in a different session with the `user2`;
• Open a Guided Decision Table with the `user1`;
• Open the same Guided Decision Table with the `user2`;
• Open the "Overview" tab with the `user1`;
• Append a new row with values in the GDT with `user2`;
• See that the GDT is not locked for the `user1`.