ipfs object patch append-data shouldn't return links in the HTTP Api

[RichardLitt]

🐕  curl -i -X POST -F "data=@test" "http://localhost:5001/api/v0/object/patch/append-data?arg=/ipfs/QmW2WQi7j6c7UgJTarActp7tDNikE4B2qXtFCfLPdsgaTQ/cat.jpg"
HTTP/1.1 100 Continue

HTTP/1.1 200 OK
Access-Control-Allow-Headers: X-Stream-Output, X-Chunked-Output, X-Content-Length
Access-Control-Expose-Headers: X-Stream-Output, X-Chunked-Output, X-Content-Length
Content-Type: application/json
Server: go-ipfs/0.4.1-dev
Trailer: X-Stream-Error
Date: Tue, 19 Apr 2016 19:29:07 GMT
Transfer-Encoding: chunked

{"Hash":"Qmd286K6pohQcTKYqnS1YhWrCiS4gz7Xi34sdwMe9USZ7u","Links":null}

[RichardLitt]

Please remove the Links field, basically.

[RichardLitt]

Same for add-link.

[RichardLitt]

Same for rm-link.