Bugs that haven't been fixed should have a "null" fix section

[ChrisTimperley]

An example of a bug that breaks this rule:

https://github.com/robust-rosin/robust/blob/master/care-o-bot/0000000/0000000.bug

[gavanderhoorn]

I guess in that example the issue was fixed, but it didn't require a code change, hence no commit to point to?

[ChrisTimperley]

Interesting. Should we really consider that example to be a bug in that case? (Either way, it seems like a null or other special value should be used for the fix section.)

[hsd-dev]

Maybe this bug got left out. Others have been set to null in 85a8ba1. Will take a look again.