net: document UDPConn.ReadFromUDPAddrPort's AddrPort result more
Clarify the form of its IPv4 addresses when listening on an
unspecified address.
(found while testing/reviewing CL 399454)
Change-Id: I62b367f5a4e6d340eb72dd7ec342080f1821e63e
Reviewed-on: https://go-review.googlesource.com/c/go/+/419614 Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>