Bug 1453760 - Fix commenter's check_needswork_owner() (#3874)
Bug 1453760 - Fix commenter's check_needswork_owner() (#3874)

change logic so that it always updates whiteboard status,
unless whiteboard_needswork_owner already exists. 
KWierso/treeherder,edmorley/treeherder,KWierso/treeherder,edmorley/treeherder,KWierso/treeherder,edmorley/treeherder,edmorley/treeherder,KWierso/treeherder