Checking schema::is_dense() is not enough to know whether row marker
should be inserted or not as there may be compact storage tables that
are not considered dense (namely, a table with now clustering key).
Row marker should only be insterted if schema::is_cql3_table() is true.
Fixes#931.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
Message-Id: <1456834937-1630-1-git-send-email-pdziepak@scylladb.com>