Some virt drivers such as ironic virt driver doesn't implement a
method to get host uptime. For such drivers, hypervisor show command
displays no information although these drivers provides other host
information.
This patch fixes the command to display hypervisor information in case
where a virt driver doesn't provide host uptime by ignoring a
HTTPNotImplemented exception.
Change-Id: I7bcca5862cd9c05aadaf6192cb80aa651cd77cad
Closes-Bug: 1612065
98bafda7e9