optimize, use info from tx to verify the request.

[todo]

aelf-web-wallet/app/service/crossTransactions.js

Lines 19 to 24 in 55ce713

	// TODO: optimize, use info from tx to verify the request.
	const key = ellipticEc.keyFromPublic(public_key, 'hex');
	return key.verify(address, signed_address);
	}
	class CrossTransactionsService extends Service {

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This issue was generated by todo based on a TODO comment in 55ce713 when #56 was merged. cc @AElfProject.