Fix the case where the distinct is applicable

[bobylito]

@redox said :

Beware, you can use distinct=true if there are no facet filters, but some tag filters or some numeric filters or a query.

So probably something like:

if (!query && facetFilters.length === 0 && numericFilters.length === 0 && tagFilters.length === 0) {
  distinct = false;
}

[bobylito]

will be finished when tags are correctly implemented! see #91