Update privacy policy with regards to logging for security and performance issues

[karlcow]

We landed #245 which adds capabilities for logging, we need to update the privacy policy if we want to log things related to the user such as an ip address.

[miketaylr]

Not ready to merge yet, until we have log creation and deletion in place.

[miketaylr]

Mike: land ur code

[karlcow]

@miketaylr ping. Cleaning https://github.com/webcompat/webcompat.com/milestone/31 before Taipei.