Don't translate debug level logs in nova.cmd and nova.db

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: I8fa50e469384f4b626ae6aa47e9ca0b8e29da404
Merge "Don't translate debug level logs in nova.cmd and nova.db"