Don't translate debug level logs in nova.spice, storage, tests and vnc

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: I5964d2f6a4328b91d67c0d8fd514e1eb7c6048bb
Merge "Don't translate debug level logs in nova.spice, storage, tests and vnc"