sstables: do not swallow exception when reading TOC
sstables: do not swallow exception when reading TOC

That caused problem when refreshing a sstable with bad permissions.

Signed-off-by: Raphael S. Carvalho <1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@scylladb.com>
Message-Id: <48e5322c53234209e55da05c64c99b8ec4e190a3.1477372974.git.1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@scylladb.com>

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