when we run "system dns-modify" command, the command will response after
sysinv-db was updated, and file "/etc/resolv.conf" will be updated
asynchronously by another process "sysinv-agent". Once the attr
"_ihost_personality" of agent is None(initial value), it will not update
file "/etc/resolv.conf" and will not inform sysinv client also,
which will lead command dns-modify failed silently.
This patch will retry function iconfig_update_file by which sysinv-agent
update file "/etc/resolv.conf" when attr "_ihost_personality" is None.
Closes-bug: 1812269
Change-Id: I3a0437750a53607c04932c1b9b818e83903bb28b
Signed-off-by: SidneyAn <ran1.an@intel.com>
53b9e46615