schema.js/load masks schema load errors

[ptitzler]

Trying to insert/update rows using the /rows endpoints, SSS returned

"statusCode":404,"body":"{\"error\":\"COL1 is not a valid parameter,COL2 is not a valid parameter,COL3 is not a valid parameter,COL4 is not a valid parameter\",\"reason\":\"Validation failure\"

Debugging the issue I noticed that an error occurred loading the schema. However, that error is not propagated and an empty default schema is returned ...

seamsdb.get("schema", function(err, data) {
    if (err) {
      return callback(null, defaultSchema);
    }
    callback(err, data);
  });

... causing validation failures because COL1, COL2 etc are unknown.