updateAllowedSubscriptions should emit a AllowedSubscriptionsUpdate event and not for a single one

[StErMi]

@dannypostma I would not bother to waste gas to recreate the array of subs that have changed, just emit the events passing the same params of the function.

While it's true that some subscriptions won't change value (because the value is the same) the end result would be that the contract will have the allow list equal to the one specified in the function param (if you didn't specify a 0x address to be allowed)