currently this command tries to fetch extra_specs for any flavor
that does not have them (which is quite usual), regardless if the
command was even asked to display them (--long) at all.
This significantly slows down this command as it makes a lot of
unnecessary REST calls, one per each flavor to fetch extra_specs for.
With this patch, client only attempts to fetch flavor extra_specs if
the user actually called the client with --long.
Change-Id: Ia36414d891a41b641d7a9a04f0a1e7d43cfee351
Story: 2010343
Task: 46484
ec8dba29f9