sstables: may_contain_rows: always true for old formats
sstables: may_contain_rows: always true for old formats

the min/max column names metadata can be trusted only
starting the md format, so just always return `true`
for older sstable formats.

Note that we could achieve that by clearing the min/max
metadata in set_clustering_components_ranges but we choose
not to do so since it disturbs sstable unit tests

Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@scylladb.com>

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