cql3: Prevent unhandled exception for anonymous user
cql3: Prevent unhandled exception for anonymous user

Since `validate` is called after `check_access`, an anonymous user would
not get the expected error message about restrictions on anonymous
users.

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