Fix incorrect "is not" testing for a a value that isn't None or empty string

tag-0.18-20220220

Fix incorrect 'is not' testing for a a value that isn't None or empty…

See CHANGELOG tag-0.18-20210905e

See CHANGELOG tag-0.18-20210905e

See CHANGELOG tag-0.18-20210905d

See CHANGELOG tag-0.18-20210905d

See CHANGELOG tag-0.18-20210905c

See CHANGELOG tag-0.18-20210905c

See CHANGELOG tag-0.18-20210905b

See CHANGELOG tag-0.18-20210905b

See CHANGELOG tag-0.18-20210905

See CHANGELOG tag-0.18-20210905