Flush cache on function get_rows()

[Syrka]

Function get_rows() without query param returns the right value, but if following you use get_rows(query='...'), with a query param, the result is wrong, and it returns the same as get_rows().

The problem is the condition if self.query is not None and self.query != new_query: in function get_rows(), because you have to do the _flush_cache()

I've just deleted self.query is not None, and now it works perfectly.