Remove redundant leading zeroes in PEP references.
diff --git a/Doc/library/contextlib.rst b/Doc/library/contextlib.rst
index 610c0b0..c88dd23 100644
--- a/Doc/library/contextlib.rst
+++ b/Doc/library/contextlib.rst
@@ -135,7 +135,7 @@
 
 .. seealso::
 
-   :pep:`0343` - The "with" statement
+   :pep:`343` - The "with" statement
       The specification, background, and examples for the Python :keyword:`with`
       statement.