Fix check on empty dataset

Without this fix we read empty datasets that resulted in several
warnings.

Signed-off-by: Claudio Usai <[email protected]>

Author: claudious96

suzieq/db/parquet/parquetdb.py

@@ -129,7 +129,7 @@ def read(self, table_name: str, data_format: str,
                     dataset = ds.dataset(elem, format='parquet',
                                          partitioning='hive')
 
-                    if not dataset:
+                    if not dataset.files:
                         continue
 
                     tmp_df = self._process_dataset(dataset, namespace, start,