Remember queue source when reading messages

[nvkelso]

From @rmarianski on December 16, 2016 16:41

For messages that get enqueued in the custom top priority queue, the current behavior is try to acknowledge them in a different queue based on its zoom level, which fails.

Instead of calculating the queue on acknowledgement, it should get threaded through the pipeline.

Copied from original issue: tilezen/vector-datasource#1146

[nvkelso]

From @rmarianski on December 16, 2016 20:49

Not sure why I created this issue in vector-datasource. The tilequeue repo would have been more appropriate.

[rmarianski]

Deployed to prod.