Remove blank spaces

Author: gaogaotiantian

Lib/test/test_pdb.py

@@ -4692,7 +4692,7 @@ def test_readline_not_imported(self):
         """GH-138860
         Directly or indirectly importing readline might deadlock a subprocess
         if it's launched with process_group=0 or preexec_fn=setpgrp
-        
+
         It's also a pattern that readline is never imported with just import pdb.
 
         This test is to ensure that readline is not imported for import pdb.