[logging] Logger: ensure a log target is added only once
[logging] Logger: ensure a log target is added only once

christianparpart/x0,xzero/x0,xzero/x0,xzero/x0,xzero/x0,christianparpart/x0,christianparpart/x0,xzero/x0,christianparpart/x0,xzero/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0