Fix indentation of versionadded directive in IPv4Address.reverse_pointer docs
diff --git a/Doc/library/ipaddress.rst b/Doc/library/ipaddress.rst
index 2df2804..9db0a70 100644
--- a/Doc/library/ipaddress.rst
+++ b/Doc/library/ipaddress.rst
@@ -156,7 +156,7 @@
       This is the name that could be used for performing a PTR lookup, not the
       resolved hostname itself.
 
-   .. versionadded:: 3.5
+      .. versionadded:: 3.5
 
    .. attribute:: is_multicast