remove go-simple-db references from go-slog

- ref: https://github.com/GigaOM/legacy-pro/issues/3806
- particularly this [comment](https://github.com/GigaOM/legacy-pro/issues/3806#issuecomment-49641387)
- accompanying config: https://github.com/GigaOM/gigaom/pull/4903

That Loggly is used behind the scenes is about as significant to go-slog as SimpleDB was.

This is also misleading, since it's not a generic Loggly viewer, but a viewer specific for go-slog items.