[Postgres Destination] connector can't insert data with the "key" in lowercase

Postghres Destination connector can't insert data with the "key" in lowercase
Example:
if the "key" in lowercase is used in the configuration in the source connector. And in the payload, the "key" is transferred in the uppercase.

Logs:
2022-05-12T07:52:41+00:00 ERR acker node stopped without processing all messages error="dropped 3 messages when stopping acker node" component=AckerNode node_id=7de377e6-efe3-45de-acc7-f39695fc5e76-acker pipeline_id=224bf6bd-5cef-4957-a181-880910f41d55 stack=[{"file":"/Users/serhii/conduit/pkg/pipeline/stream/acker.go","func":"[github.com/conduitio/conduit/pkg/pipeline/stream.(*AckerNode](http://github.com/conduitio/conduit/pkg/pipeline/stream.(*AckerNode)).teardown","line":133}] 2022-05-12T07:52:41+00:00 ERR node stopped error="node 7de377e6-efe3-45de-acc7-f39695fc5e76-acker stopped with error: error receiving ack: insert exec failed: ERROR: column \"id\" specified more than once (SQLSTATE 42701)" component=pipeline.Service node_id=7de377e6-efe3-45de-acc7-f39695fc5e76-acker stack=[{"file":"/Users/serhii/conduit/pkg/pipeline/lifecycle.go","func":"[github.com/conduitio/conduit/pkg/pipeline.(*Service](http://github.com/conduitio/conduit/pkg/pipeline.(*Service)).runPipeline.func1","line":387},{"file":"/Users/serhii/conduit/pkg/connector/destination.go","func":"[github.com/conduitio/conduit/pkg/connector.(*destination](http://github.com/conduitio/conduit/pkg/connector.(*destination)).Ack","line":194},{"file":"/Users/serhii/conduit/pkg/plugin/builtin/v1/destination.go","func":"[github.com/conduitio/conduit/pkg/plugin/builtin/v1.(*destinationPluginAdapter](http://github.com/conduitio/conduit/pkg/plugin/builtin/v1.(*destinationPluginAdapter)).Ack","line":137}]