Fix integration config forms to show local site when fieldsets exist.
Review Request #1080 — Created Feb. 16, 2018 and updated
All integration configs for Review Board automatically include a local site field. In the case where there were no fieldsets, all the fields would show up fine, but if the form tried to group things, the local site field would disappear. This is because the djblets form was defining the basic info fieldset with only the "name" and "enable" fields. I've fixed the Review Board form to properly override the basic info fieldset, so that local site shows up everywhere. Testing done: Loaded some integration config forms that previously exhibited a missing "Local Site" field. Saw the field appear. Reviewed at https://reviews.reviewboard.org/r/9604/