<!-- Describe the issue -->
`getrawtransaction` fails
<!--- What behavior did you expect? -->
Return decoded raw tx
<!--- What was the actual behavior (provide screenshots if the issue is GUI-related)? -->
* `bitcoin-qt -prune=8192  -server -rpcuser=rpc -rpcpassword=rpc -onlynet=ipv4 -rpcbind=127.0.0.1:18332 -testnet`
  * BTC 0.18.0
  * `getrawtransaction b423b2b22d6d74376de2887c07f7c84ae890a93d541fcc6dbf3686f2923b2753 1`
![image](https://user-images.githubusercontent.com/3670331/58841021-658d7180-8668-11e9-9f9f-ed1f794070ea.png)
  * BTC 0.17.1
  * `getrawtransaction b423b2b22d6d74376de2887c07f7c84ae890a93d541fcc6dbf3686f2923b2753 1`
![image](https://user-images.githubusercontent.com/3670331/58841089-9ff70e80-8668-11e9-8a68-5022631b43d7.png)

<!--- How reliably can you reproduce the issue, what are the steps to do so? -->
Request `getrawtransaction`.
<!-- What version of Bitcoin Core are you using, where did you get it (website, self-compiled, etc)? -->
Official from site.
<!-- What type of machine are you observing the error on (OS/CPU and disk type)? -->
`Linux pentagon 4.9.0-9-amd64 #1 SMP Debian 4.9.168-1+deb9u2 (2019-05-13) x86_64 GNU/Linux`, u5200, 2x8Gb, SSD
<!-- For the GUI-related issue on Linux provide names and versions of a distro, a desktop environment and a graphical shell (if relevant). -->
QT
<!-- Any extra information that might be useful in the debugging process. -->
<!--- This is normally the contents of a `debug.log` or `config.log` file. Raw text or a link to a pastebin type site are preferred. -->

{
    if (request.fHelp || request.params.size() < 2 || request.params.size() > 4)
        throw std::runtime_error(
            RPCHelpMan{"signrawtransactionwithkey",
                "\nSign inputs for raw transaction (serialized, hex-encoded).\n"
                "The second argument is an array of base58-encoded private\n"
                "keys that will be the only keys used to sign the transaction.\n"
                "The third optional argument (may be null) is an array of previous transaction outputs that\n"
                "this transaction depends on but may not yet be in the block chain.\n",
                {
                    {"hexstring", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction hex string"},
                    {"privkeys", RPCArg::Type::ARR, RPCArg::Optional::NO, "A json array of base58-encoded private keys for signing",
                        {
                            {"privatekey", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "private key in base58-encoding"},
                        },
                        },
                    {"prevtxs", RPCArg::Type::ARR, RPCArg::Optional::OMITTED_NAMED_ARG, "A json array of previous dependent transaction outputs",
                        {
                            {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                                {
                                    {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
                                    {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The output number"},
                                    {"scriptPubKey", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "script key"},
                                    {"redeemScript", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "(required for P2SH) redeem script"},