Fix IDE warnings (#12281)

### What problem does this PR solve?

As title

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

rag/app/presentation.py

@@ -249,7 +249,9 @@ def chunk(filename, binary=None, from_page=0, to_page=100000,
 if __name__ == "__main__":
     import sys
 
+
     def dummy(a, b):
         pass
 
+
     chunk(sys.argv[1], callback=dummy)