Bug#842808: gant: FTBFS: Cannot add task ':gant:install' as a task with that name already exists

[殷啟聰]

Control: tags -1 + fixed

Thank you for the report. I believe this bug is fixed by
<https://anonscm.debian.org/cgit/pkg-java/gant.git/commit/?id=e62c12f0806aceb1f6ccabcd1be4574ed0d042d6>.