bugtrackers: add 'Scoping' as an open status to Jira

bugs in Jira with the status set as 'Scoping' should be considered as open bugs.

@mupuf I'm wondering if it may be best to add a model field to allow the specifying of what qualifies as an open status rather than hardcoding. We could keep 'Open', obviously, and then just append the other values specified by the user. Just a thought.