docs: update ResultSet.current_rows wrt empty pages

ScyllaDB may send empty pages when processing long spans of
tombstones to avoid timing out; adjust the documentation not
to imply that an empty page means there is no more data.

Author: avikivity

cassandra/cluster.py

@@ -5405,8 +5405,8 @@ def has_more_pages(self):
     @property
     def current_rows(self):
         """
-        The list of current page rows. May be empty if the result was empty,
-        or this is the last page.
+        The list of current page rows. May be empty; this does not mean
+        there is no more data. Use `has_more_pages()` for that.
         """
         return self._current_rows or []