connection errors blocking db syncs

[Chris Ricker]

AIO run in an 8 gig VM shows errors like:

Debug: Exec[glance-manage db_sync](provider=posix): Executing 'glance-manage db_sync'
Debug: Executing 'glance-manage db_sync'
Notice: /Stage[main]/Glance::Registry/Exec[glance-manage db_sync]/returns: 2014-04-08 13:55:13.265 11613 CRITICAL glance [-] OperationalError: (OperationalError) (1129, "Host 'rtp-chricker-8915.cisco.com' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'") None None
Error: /Stage[main]/Glance::Registry/Exec[glance-manage db_sync]: Failed to call refresh: glance-manage db_sync returned 1 instead of one of [0]
Error: /Stage[main]/Glance::Registry/Exec[glance-manage db_sync]: glance-manage db_sync returned 1 instead of one of [0]

for every db sync

consequence is that db tables don't get populated

[Chris Ricker (chris-ricker)]

https://review.openstack.org/88033

Less ugly approaches welcomed!