Non optimal usage `pg_dump` / `pg_restore`

Due to the hive#524 (closed) a problem has been uncovered. It seems that pg_dump and pg_restore work by transferring data in text format.

How to repeat:

It is possible, but before fixing hive#524 (closed), because a lack of this fix triggers an assertion.

For select '{"type":"account_update_operation","value":{"account":"nathan","owner":{"weight_threshold":1,"account_auths":[],"key_auths":[["STM6QRHUtxiEbD1CF4YNNBHyVwTasmTirNArHzXmXyeVvT5E2YFPw",1]]},"memo_key":"STM1111111111111111111111111111111114T1Anm","json_metadata":""}}'::hive.operation

we get

ERROR:  Assert Exception:my->_key != empty_pub: 
LINE 1: select '{"type":"account_update_operation","value":{"account...

Originally dumping and restoring a 5mln database triggers this assertion.