storage_service: improve log message for refresh
storage_service: improve log message for refresh

'No new SSTables were found for keyspace1.standard1' was printed
if user uploaded new sstables to upload dir instead, and that is
confusing. We should instead print that if new sstables weren't
found in both cf and cf/upload dirs.

Signed-off-by: Raphael S. Carvalho <1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@scylladb.com>
Message-Id: <90386f6255407697434213227ae7ff0de7464f99.1475535203.git.1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@scylladb.com>

avikivity/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,scylladb/scylla,raphaelsc/scylla,avikivity/scylla,raphaelsc/scylla,raphaelsc/scylla,scylladb/scylla,duarten/scylla