Update i18n translation for neutron.agents log msg's

Update i18n translation for neutron.agents log msg's

Don't translate debug level logs and enforce log hints
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 neutron doesn't support lazy translation yet).

NOTE: this is done on a directory by directory basis to ensure that we
do not have too many conflicts and rebases.

Add a local hacking rule to enforce this.

This patch set enforces the directory neutron/agents

Partial-bug: #1320867

Change-Id: I4bd562e5138c2d2850072440aa121f27e902463a