bpo-43990: Fix the footnote ordering in the operator precedence docs (GH-25805)

Footnotes 5 and 6 were in the wrong order.
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index 5b15376..5ad640a 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -1920,8 +1920,8 @@
    the :keyword:`is` operator, like those involving comparisons between instance
    methods, or constants.  Check their documentation for more info.
 
-.. [#] The ``%`` operator is also used for string formatting; the same
-   precedence applies.
-
 .. [#] The power operator ``**`` binds less tightly than an arithmetic or
    bitwise unary operator on its right, that is, ``2**-1`` is ``0.5``.
+
+.. [#] The ``%`` operator is also used for string formatting; the same
+   precedence applies.