fixed empty line bug

saqc/core/reader.py

@@ -85,7 +85,7 @@ def _expandVarnameWildcards(config: Config, data: pd.DataFrame) -> Config:
 
 def _clearRows(rows: Iterable[List[str]], comment: str = "#") -> Iterator[Tuple[str, List[Any]]]:
     for i, row in enumerate(rows):
-        if not row[0].lstrip().startswith(comment):
+        if row and not row[0].lstrip().startswith(comment):
             row = [c.split(comment)[0].strip() for c in row]
             yield i, row