test unit: remove a duplicated test
test unit: remove a duplicated test

It's covered by test/command/suite/.

komainu8/groonga,komainu8/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,groonga/groonga,komainu8/groonga,komainu8/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,groonga/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga,komainu8/groonga,komainu8/groonga,komainu8/groonga,komainu8/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga