
<!-- Describe the issue -->
Following commit 46004790588c24174a0bec49b540d158ce163ffd (@achow101), `decodepsbt` overstates the fee, apparently including both the `witness_utxo` and `non_witness_utxo` amounts in the inputs.

**Expected behavior**

The decoded fee should be the sum of the inputs, minus the sum of the outputs.

**Actual behavior**

The decoded fee is exactly twice the amount of the inputs, minus the sum of the outputs.

**To reproduce**

Build any PSBT using `createpsbt`, `walletprocesspsbt`, then decode it with `decodepsbt`. See the `fee` field in the JSON.

**System information**

I compiled myself from 5550fa5983ea59e7ccef6540b7ec49a1770fb3ca on Whonix 14.

Then I did `git revert 46004790588c24174a0bec49b540d158ce163ffd ` and the problem went away.

{
                                        {RPCResult::Type::STR, "asm", "The asm"},
                                        {RPCResult::Type::STR_HEX, "hex", "The hex"},
                                        {RPCResult::Type::STR, "type", "The type, eg 'pubkeyhash'"},
                                        {RPCResult::Type::STR, "address"," Bitcoin address if there is one"},
                                    }},
                                }},
                                {RPCResult::Type::OBJ_DYN, "partial_signatures",  true, "",
                                {
                                    {RPCResult::Type::STR, "pubkey", "The public key and signature that corresponds to it."},
                                }},
                                {RPCResult::Type::STR, "sighash",  true, "The sighash type to be used"},
                                {RPCResult::Type::OBJ, "redeem_script",  true, "",
                                {
                                    {RPCResult::Type::STR, "asm", "The asm"},
                                    {RPCResult::Type::STR_HEX, "hex", "The hex"},
                                    {RPCResult::Type::STR, "type", "The type, eg 'pubkeyhash'"},
                                }},
                                {RPCResult::Type::OBJ, "witness_script",  true, "",
                                {
                                    {RPCResult::Type::STR, "asm", "The asm"},
                                    {RPCResult::Type::STR_HEX, "hex", "The hex"},
                                    {RPCResult::Type::STR, "type", "The type, eg 'pubkeyhash'"},
                                }},
                                {RPCResult::Type::ARR, "bip32_derivs",  true, "",
                                {
                                    {RPCResult::Type::OBJ, "pubkey",  true, "The public key with the derivation path as the value.",
                                    {
                                        {RPCResult::Type::STR, "master_fingerprint", "The fingerprint of the master key"},
                                        {RPCResult::Type::STR, "path", "The path"},