Remove enforcement for different wallets for deal collateral and publish storage deals message

[nonsense]

Currently Boost requires two addresses for storage deals. Sometimes it is not a simple case to add a new control address, as it needs to be set from the owner which could be held by another business (aka not the SP).

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	if walletPSD.String() == walletCP.String() {
		return nil, fmt.Errorf("wallets for PublishStorageDeals and deal collateral must be different")
	}

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Make it possible to initialise Boost with fewer wallets, or with a single wallet.

Related to: #726