wallet: loading, log descriptor parsing error details

The `UNKNOWN_DESCRIPTOR` error comes from the
`WalletDescriptor::DeserializeDescriptor` std::ios_base
exception, which contains further information about the
parsing error.

src/wallet/walletdb.cpp

@@ -794,11 +794,13 @@ static DBErrors LoadDescriptorWalletRecords(CWallet* pwallet, DatabaseBatch& bat
         WalletDescriptor desc;
         try {
             value >> desc;
-        } catch (const std::ios_base::failure&) {
+        } catch (const std::ios_base::failure& e) {
             strErr = strprintf("Error: Unrecognized descriptor found in wallet %s. ", pwallet->GetName());
             strErr += (last_client > CLIENT_VERSION) ? "The wallet might had been created on a newer version. " :
                     "The database might be corrupted or the software version is not compatible with one of your wallet descriptors. ";
             strErr += "Please try running the latest software version";
+            // Also include error details
+            strErr = strprintf("%s\nDetails: %s", strErr, e.what());
             return DBErrors::UNKNOWN_DESCRIPTOR;
         }
         pwallet->LoadDescriptorScriptPubKeyMan(id, desc);