change .on() to .once() when shard transferStatus emits a finish event
change .on() to .once() when shard transferStatus emits a finish event

bookchin/orc,aleitner/core,Storj/core,retrohacker/core,orcproject/orc,bookchin/orc,gordonwritescode/storj-core,Storj/node-storj,orcproject/orc