Remove LegacyFormatter from logging_sample.conf
Remove LegacyFormatter from logging_sample.conf

manila.openstack.common.log.LegacyFormatter no longer exists.
This change removes it from logging_sample.conf.

Change-Id: I67daa0e11458272c0a67bd0754c00902d36e27ef
Closes-Bug: #1499263

NetApp/manila,openstack/manila,vponomaryov/manila,bswartz/manila,bswartz/manila,vponomaryov/manila,NetApp/manila,openstack/manila,scality/manila,scality/manila