[libvirt] [PATCH] esx: Add the actual product version to the error message.

[Richard W.M. Jones]

This is just an old patch I had from when I was trying to use the
'esx://' URI scheme to access a vCenter resource (which turns out to
use 'vpx://' instead, which was the problem I was having).

It's useful for debugging purposes to print the actual product version
from the server in the error message.

Rich.