<!-- 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. -->

+ HelpExampleRpc("getrawtransaction", "\"mytxid\", true")
            + HelpExampleCli("getrawtransaction", "\"mytxid\" false \"myblockhash\"")
            + HelpExampleCli("getrawtransaction", "\"mytxid\" true \"myblockhash\"")
                },
    };
    if (request.fHelp || !help.IsValidNumArgs(request.params.size())) {
        throw std::runtime_error(help.ToString());
    }
    bool in_active_chain = true;
    uint256 hash = ParseHashV(request.params[0], "parameter 1");
    CBlockIndex* blockindex = nullptr;
    if (hash == Params().GenesisBlock().hashMerkleRoot) {
        
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "The genesis block coinbase is not considered an ordinary transaction and cannot be retrieved");
    }
    
    bool fVerbose = false;
    if (!request.params[1].isNull()) {
        fVerbose = request.params[1].isNum() ? (request.params[1].get_int() != 0) : request.params[1].get_bool();
    }
    if (!request.params[2].isNull()) {
        LOCK(cs_main);
        uint256 blockhash = ParseHashV(request.params[2], "parameter 3");
        blockindex = LookupBlockIndex(blockhash);
        if (!blockindex) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block hash not found");
        }
        in_active_chain = ::ChainActive().Contains(blockindex);
    }
    bool f_txindex_ready = false;