Fix unexpected stdout redirection

Remove a line that replaces sys.stdout with sys.stderr, which causes
unexpected side-effects to the program.

src/__init__.py

@@ -2389,7 +2389,6 @@ def set_word_spacing(self, spacing):
 
     def span_bottom(self):
         """Find deepest level in stacked spans."""
-        sys.stdout = sys.stderr
         parent = self
         child = self.last_child
         if child is None: