dist/common/scripts/scylla_setup: fix typo on interactive setup
dist/common/scripts/scylla_setup: fix typo on interactive setup

Scylls -> Scylla

Fixes #3656

Signed-off-by: Takuya ASADA <4ebfb6f510af412d6e89fefa3ab96d9c8b5e3fff@scylladb.com>
Message-Id: <20180808002443.1374-1-4ebfb6f510af412d6e89fefa3ab96d9c8b5e3fff@scylladb.com>

avikivity/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla