Add setting for islands to auto toggle fly

[ChimpGamer]

Description

Is your feature request related to a problem?

Players often forget to toggle their fly back on when they have been on spawn which causes players to die in some situations.

Describe the solution you'd like us to implement.

So it would be great for players to have an island setting that allows them to auto toggle the setting.

Describe alternatives you've considered.

Additional context

[tastybento]

Tell me more about the scenario that causes the players to die. Can you explain the steps that would cause this?

[ChimpGamer]

Some plugins like Essentials and CMI disable fly on login when players don't have permission to auto enable fly on login. I've given permission for this but it seems that IslandFly only enables player to allow fly but doesn't really enable fly which makes the fall out of the sky if the logout above the void.