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) {
```
error = AmountErrMsg("consolidatefeerate", args.GetArg("-consolidatefeerate", ""));
            return nullptr;
        }
    }
    if (chain && chain->relayMinFee().GetFeePerK() > HIGH_TX_FEE_PER_KB) {
        warnings.push_back(AmountHighWarn("-minrelaytxfee") + Untranslated(" ") +
                           _("Th will avoid paying less than the minimum relay fee."));
    }
    Instance->m_confirm_target = args.GetIntArg("-txconfirmtarget", DEFAULT_TX_CONFIRM_TARGET);
    Instance->m_spend_zero_conf_change = args.GetBoolArg("-spendzeroconfchange", DEFAULT_SPEND_ZEROCONF_CHANGE);
    Instance->m_signal_rbf = args.GetBoolArg("-rbf", DEFAULT_WALLET_RBF);
    Instance->WalletLogPrintf("Wallet completed loading in %15dms\n", GetTimeMillis() - nStart);
    // Try to top up keypool. No-op if th is locked.
    Instance->TopUpKeyPool();
    if (chain && !AttachChain(Instance, *chain, rescan_required, error, warnings)) {
        return nullptr;
    }
    {
        LOCK(Instance->cs_);
        Instance->SetBroadcastTransactions(args.GetBoolArg("-broadcast", DEFAULT_WALLETBROADCAST));
        Instance->WalletLogPrintf("setKeyPool.size() = %u\n",      Instance->GetKeyPoolSize());
        Instance->WalletLogPrintf("mapWallet.size() = %u\n",       Instance->mapWallet.size());
        Instance->WalletLogPrintf("m_address_book.size() = %u\n",  Instance->m_address_book.size());
    }
    return Instance;
}
bool CWalletAttachChain(const stdshared_ptr<CWallet>& Instance, interfacesChain& chain, const bool rescan_required, bilingual_str& error, stdvector<bilingual_str>& warnings)
{
    LOCK(Instance->cs_);
    // allow setting the chain if it hasn't been set already but prevent changing it