Update traffic log doc to note logging impact on performance
Update traffic log doc to note logging impact on performance

[#148802413]

Signed-off-by: Angela Chin <09c3fe443cd90255b3ab6945ab331bb5cdf11ccb@pivotal.io>

cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release