Fixed the bug that showed on the result page, in the constraint section, the text IS NULL or IS NOT NULL twice for a null constraint.
Fixed the bug that showed on the result page, in the constraint section, the text IS NULL or IS NOT NULL twice for a null constraint.


Former-commit-id: 96dd7a7d3ed1f7275b4a9825859a9939910e3fde
julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine