Attempting to load a wallet with an unknown descriptor causes a fatal error:

```
2022-09-06T01:51:06Z init message: Loading wallet…
2022-09-06T01:51:06Z [descriptor] Invalid descriptor: Can only have tr at top level: iostream error
2022-09-06T01:51:06Z [descriptor] Invalid descriptor: Can only have tr at top level: iostream error
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 50e6032b4d1d62c020ebb6a4d0c8fafc6f01ea80f4d2a41c1a256086611636e9, type = legacy, internal = false
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 7f709abbde61e8c253798375692bf41202e625ed74a65f9474d464be34fb2870, type = p2sh-segwit, internal = false
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 2dc6c34099e0ca1235fc990a51042967ecbc8c8ac57062f964739cba2f451be8, type = bech32, internal = false
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 8d3c63ea1ac9936e789713dc8bae857d328ff029ab9392e67c716752e9b11b0c, type = bech32m, internal = false
2022-09-06T01:51:06Z [descriptor] Releasing wallet
2022-09-06T01:51:06Z 

************************
EXCEPTION: St12out_of_range       
map::at       
bitcoin in Runaway exception       



************************
EXCEPTION: St12out_of_range       
map::at       
bitcoin in Runaway exception       

bitcoin-qt: ./checkqueue.h:204: CCheckQueue<CScriptCheck>::~CCheckQueue() [T = CScriptCheck]: Assertion `m_worker_threads.empty()' failed.
Aborted
```

> A fatal error occurred. Bitcoin Core can no longer continue safely and will quit.

To reproduce, a quick hack:

```c++
--- a/src/script/descriptor.cpp
+++ b/src/script/descriptor.cpp
@@ -1408,7 +1408,7 @@ std::unique_ptr<DescriptorImpl> ParseScript(uint32_t& key_exp_index, Span<const
         error = "Can only have addr() at top level";
         return nullptr;
     }
-    if (ctx == ParseScriptContext::TOP && Func("tr", expr)) {
+    if (ctx == ParseScriptContext::TOP && Func("trx", expr)) {
         auto arg = Expr(expr);
         auto internal_key = ParsePubkey(key_exp_index, arg, ParseScriptContext::P2TR, out, error);
         if (!internal_key) {
```
if (tx->HasWitness() && !wtx.tx->HasWitness()) {
            wtx.SetTx(tx);
            fUpdated = true;
        }
    }
    //// 
    WalletLogPrintf("AddToWallet %s  %s%s\n", hash.ToString(), (fInsertedNew ? "new"  ""), (fUpdated ? "update"  ""));
    // W
    if (fInsertedNew || fUpdated)
        if (!batch.WriteTx(wtx))
            return nullptr;
    // B
    wtx.MarkDirty();
    // N
    NotifyTransactionChanged(hash, fInsertedNew ? CT_NEW  CT_UPDATED);
#if HAVE_SYSTEM
    // n
    stdstring strCmd = m_args.GetArg("-notify", "");
    if (!strCmd.empty())
    {
        ReplaceAll(strCmd, "%s", hash.GetHex());
        if (auto* conf = wtx.state<TxStateConfirmed>())
        {
            ReplaceAll(strCmd, "%b", conf->confirmed_block_hash.GetHex());
            ReplaceAll(strCmd, "%h", ToString(conf->confirmed_block_height));
        } else {
            ReplaceAll(strCmd, "%b", "unconfirmed");
            ReplaceAll(strCmd, "%h", "-1");
        }
#ifndef WIN32