[Forseti] Seating page is wrong state if players count changes before seating approval

[ctizen]

Steps to reproduce:

• Exclude a table from seating on players manage page
• Make a seating on games manage page
• Return back to players management and add the excluded table back to seating
• Return to games manage page

Page is stuck in the following state:

Page goes to proper state if admin excludes the table back. Probably we should disallow adding/removing players from seating on all game stages except "Not started".