Some config in os_vif are affecting nova behavior, so we should add them
in nova.conf.sample in order to let people fine-tune this on demand
without looking into code.
This will also change the nova config reference docs.o.o
Signed-off-by: Arnaud Morin <arnaud.morin@ovhcloud.com>
Change-Id: Icfba423fda037be9cf071022283985297a989b07
6b9342f6e2