last small fix

Author: TonioMacaronio

web3swift/PrecompiledContracts/ERC721/Web3+ERC721.swift

@@ -238,7 +238,7 @@ public class ERC721: IERC721 {
         let contract = self.contract
         var basicOptions = TransactionOptions()
         basicOptions.callOnBlock = .latest
-        let result = try contract.read("setApprovalForAll", parameters: [address, approved] as [AnyObject], extraData: Data(), transactionOptions: self.transactionOptions)!.call(transactionOptions: transactionOptions)
+        let result = try contract.read("isApprovedForAll", parameters: [address, approved] as [AnyObject], extraData: Data(), transactionOptions: self.transactionOptions)!.call(transactionOptions: transactionOptions)
         guard let res = result["0"] as? Bool else {throw Web3Error.processingError(desc: "Failed to get result of expected type from the Ethereum node")}
         return res
     }