When building the in-memory schema for a column family, we were
ignoring compaction strategy class because of a bug in the
existing code. Example: suppose that you create a column family
with leveled compaction strategy. This option would be ignored
and the default strategy (size-tiered) would be used instead.
Found this problem while working on leveled compaction.
Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>