consider removing exit_finality_margin from watcher

[InoMurko]

elixir-omg/config/config.exs

Line 164 in 1feed63

exit_finality_margin: 12,

It seems redundant because they all follow the :depositor process

elixir-omg/apps/omg_watcher/lib/omg_watcher/coordinator_setup.ex

Lines 48 to 62 in 1feed63

	exit_processor: [waits_for: :depositor, finality_margin: finality_margin],
	exit_finalizer: [
	waits_for: [:depositor, :block_getter, :exit_processor],
	finality_margin: finality_margin
	],
	exit_challenger: [waits_for: :exit_processor, finality_margin: finality_margin],
	in_flight_exit_processor: [waits_for: :depositor, finality_margin: finality_margin],
	piggyback_processor: [waits_for: :in_flight_exit_processor, finality_margin: finality_margin],
	competitor_processor: [waits_for: :in_flight_exit_processor, finality_margin: finality_margin],
	challenges_responds_processor: [waits_for: :competitor_processor, finality_margin: finality_margin],
	piggyback_challenges_processor: [waits_for: :piggyback_processor, finality_margin: finality_margin],
	ife_exit_finalizer: [
	waits_for: [:depositor, :block_getter, :in_flight_exit_processor, :piggyback_processor],
	finality_margin: finality_margin
	]

:depositor margin is 10, exit processor finality margin is 12 - what does it really give us? Also, events are fetched by the depositor with margin 10.