Issues #22989, #21228: Document HTTP response object for urlopen()

Previous documentation was not clear if the geturl(), info() and getcode()
were valid for HTTP responses. The “msg” attribute is different to the usual
HTTPResponse.msg attribute. Based on patch by Evens Fortuné.
diff --git a/Misc/ACKS b/Misc/ACKS
index a0d640d..0f64ef0 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -436,6 +436,7 @@
 Michael Foord
 Amaury Forgeot d'Arc
 Doug Fort
+Evens Fortuné
 Chris Foster
 John Fouhy
 Andrew Francis