Sometimes, during restart of dnsmasq process it may happend that
after process is killed, start attempt is made too fast, before
old process really unbind from IP address on which it was listening.
That causes an issue with starting dnsmasq process again.
In patch [1] disable() method was changed that it can wait
until process is really not active (no pid for it) but that didn't
solve the problem with starting a new dnsmasq process completely and
sometimes it still happens, at least in functional tests.
So now, enable() method is changed so that it will try to enable
dnsmasq process for 1 minute, until it will really be spawned properly.
[1] https://review.openstack.org/#/c/634390/
Change-Id: I18d73b787fa3ab8803e12d5e5eb2bb7109205aba
Closes-Bug: #1811126
(cherry picked from commit 157e09e6af)
810774b352