Should not compare instances with ==

PqlBatchQuery :
line 116:
```java
    public void add(PqlQuery query) {
        if (query.getIndex() != this.getIndex()) {
// Should be: if (!query.getIndex().getName().equals(this.getIndex().getName())) {
            throw new PilosaException("Query index should be the same as PqlBatchQuery index");
        }
        this.queries.add(query);
    }
```