belt throws a Programming exception for a malformed query when sequences are empty

[vjeeva]

When performing a sequence dump and load, if there are no sequences to dump the dump command runs fine but the load function errors out saying we have a malformed query.

This malformed query comes from there being no sequences to dump (happened on some empty databases that shouldn't have been involved anyways but still).

Please alter the code so when it runs into empty sequences - load at least calls that out or the thrown error says there were no sequences to load.