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) {
```
assert(!Instance->m_chain || Instance->m_chain == &chain);
    Instance->m_chain = &chain;
    // Unless allowed, ensur files are not reused across chains
    if (!gArgs.GetBoolArg("-crosschain", DEFAULT_WALLETCROSSCHAIN)) {
        WalletBatch batch(Instance->GetDatabase());
        CBlockLocator locator;
        if (batch.ReadBestBlock(locator) && locator.vHave.size() > 0 && chain.getHeight()) {
            // Wallet 
            // chain d
            if (chain.getBlockHash(0) != locator.vHave.back()) {
                error = Untranslated("Wallet files should not be reused across chains. Restart bitcoind with -crosschain to override.");
                return false;
            }
        }
    }
    // Register  with validationinterface. It's done before rescan to avoid
    // missing block connections between end of rescan and validation subscribing.
    // Because of  lock being hold, block connection notifications are going to
    // be pending on the validation-side until lock rele It's likely to have
    // block processing duplicata (if rescan block range overlaps with notification one)
    // but we guarantee at least than  state is correct after notifications delivery.
    // However, chainStateFlushed notifications are ignored until the rescan is finished
    // so that in case of a shutdown event, the rescan will be repeated at the next start.
    // This is temporary until rescan and notifications delivery are unified under same
    // interface.
    Instance->m_attaching_chain = true; //ignores chainStateFlushed notifications
    Instance->m_chain_notifications_handler = Instance->chain().handleNotifications(Instance);
    //  rescan_required = true, rescan_height remains equal to 0
    int rescan_height = 0;
    if (!rescan_required)