wallet: Disallow loading legacy wallets

Legacy wallets do not have the descriptors flag set. Don't load wallets
without the descriptors flag.

At the same time, we will no longer load BDB databases since they are
only used for legacy wallets.

src/wallet/init.cpp

@@ -98,11 +98,6 @@ void WalletInit::AddWalletOptions(ArgsManager& argsman) const
 
 bool WalletInit::ParameterInteraction() const
 {
-#ifdef USE_BDB
-     if (!BerkeleyDatabaseSanityCheck()) {
-         return InitError(Untranslated("A version conflict was detected between the run-time BerkeleyDB library and the one used during compilation."));
-     }
-#endif
     if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET)) {
         for (const std::string& wallet : gArgs.GetArgs("-wallet")) {
             LogPrintf("%s: parameter interaction: -disablewallet -> ignoring -wallet=%s\n", __func__, wallet);