Issue #27204: Fix doctests in Doc/howto

Patch by Jelle Zijlstra.
diff --git a/Doc/howto/ipaddress.rst b/Doc/howto/ipaddress.rst
index 5e0ff3e..452e367 100644
--- a/Doc/howto/ipaddress.rst
+++ b/Doc/howto/ipaddress.rst
@@ -1,3 +1,7 @@
+.. testsetup::
+
+   import ipaddress
+
 .. _ipaddress-howto:
 
 ***************************************
@@ -49,11 +53,6 @@
 determines whether to create an IPv4 or IPv6 address based on the passed in
 value:
 
-.. testsetup::
-   >>> import ipaddress
-
-::
-
    >>> ipaddress.ip_address('192.0.2.1')
    IPv4Address('192.0.2.1')
    >>> ipaddress.ip_address('2001:DB8::1')