Cannot remove field value by setting it to NULL

The following query:

```
 $cassandraDatabase->query('UPDATE users SET field_to_delete = :empty_value;', array('empty_value' => NULL));
```

causes the following error:

```
 BigInt value 0 not an int in /home/pako_www/live/vendor/evseevnn/php-cassandra-binary/src/Protocol/BinaryData.php on line 145
```
