add whitespace

IPython/core/debugger.py

@@ -225,6 +225,7 b' class Pdb(OldPdb):'
                 raise ValueError("Context must be a positive integer")
         except (TypeError, ValueError):
                 raise ValueError("Context must be a positive integer")
+
         # `kwargs` ensures full compatibility with stdlib's `pdb.Pdb`.
         OldPdb.__init__(self, completekey, stdin, stdout, **kwargs)