
<!-- 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{"if verbose is not set or set to false",
                         RPCResult::Type::STR, "data", "The serialized, hex-encoded data for 'txid'"
                     },
                     RPCResult{"if verbose is set to true",
                         RPCResult::Type::OBJ, "", "",
                         {
                             {RPCResult::Type::BOOL, "in_active_chain", "Whether specified block is in the active chain or not (only present with explicit \"blockhash\" argument)"},
                             {RPCResult::Type::STR_HEX, "hex", "The serialized, hex-encoded data for 'txid'"},
                             {RPCResult::Type::STR_HEX, "txid", "The transaction id (same as provided)"},
                             {RPCResult::Type::STR_HEX, "hash", "The transaction hash (differs from txid for witness transactions)"},
                             {RPCResult::Type::NUM, "size", "The serialized transaction size"},
                             {RPCResult::Type::NUM, "vsize", "The virtual transaction size (differs from size for witness transactions)"},
                             {RPCResult::Type::NUM, "weight", "The transaction's weight (between vsize*4-3 and vsize*4)"},
                             {RPCResult::Type::NUM, "version", "The version"},
                             {RPCResult::Type::NUM_TIME, "locktime", "The lock time"},
                             {RPCResult::Type::ARR, "vin", "",
                             {
                                 {RPCResult::Type::OBJ, "", "",
                                 {
                                     {RPCResult::Type::STR_HEX, "txid", "The transaction id"},
                                     {RPCResult::Type::STR, "vout", ""},
                                     {RPCResult::Type::OBJ, "scriptSig", "The script",
                                     {
                                         {RPCResult::Type::STR, "asm", "asm"},
                                         {RPCResult::Type::STR_HEX, "hex", "hex"},
                                     }},
                                     {RPCResult::Type::NUM, "sequence", "The script sequence number"},
                                     {RPCResult::Type::ARR, "txinwitness", "",
                                     {