compiz-plugins-experimental

fix for rpc fullnode crashing on massive insert of missed witness blocks causing a segfault in nudb insert() once chain is restarted after a fault...


/libraries/plugins/block_history/block_history_plugin.cpp:
```
block_history_plugin_impl::on_irreversible_block(uint32_t block_num) {
...
ilog("onirrev4");
    // insert
    ops_in_block_key new_key(block_num);
    ilog("new_key: ${new_key}", ("new_key", new_key));
    boost::system::error_code ec;
    _nudbstore_database.insert(new_key, newitem, ec);
ilog("onirrev5");
...
```