Remove sensitive data from log files

I’ve just noticed the trace log file reveals sensitive data from NZBGet (NzbgetProxy) on startup. Since api keys are removed from logfiles it’s probably a good idea to remove this information as well.

For example:
ControlUsername
ControlPassword
ServerX.Username
ServerX.Password

Given the format this is going to be much more difficult than dealing with the API key, since it wraps multiple lines and is very specific to nzbget.

Added to an existing card on Trello: https://trello.com/c/q8yj9fXh/695-cleansing-logs