ListenBucketNotification should set proper MIME type. (#4621)
ListenBucketNotification should set proper MIME type. (#4621)

This is needed to avoid proxies buffering the connection
this is also a HTTP standard way to handle this situation
where server is sending back events in asynchronously.

For more details read https://goo.gl/RCML9f

Fixes - https://github.com/minio/minio-go/issues/731
krishnasrinivas/minio,krisis/minio,NitishT/minio,fwessels/minio,rushenn/minio,fwessels/minio,harshavardhana/minio,aead/minio,dvstate/minio,harshavardhana/minio,vadmeste/minio,balamurugana/minio,NitishT/minio,harshavardhana/minio,dvstate/minio,fwessels/minio,abperiasamy/minio,aead/minio,vadmeste/minio,NitishT/minio,jimjag/minio,harshavardhana/minio,harshavardhana/minio,jimjag/minio,rushenn/minio,minio/minio,aead/minio,harshavardhana/minio,abperiasamy/minio,donatello/minio,rushenn/minio,abperiasamy/minio,aead/minio,minio/minio,donatello/minio,fwessels/minio,krishnasrinivas/minio,krishnasrinivas/minio,harshavardhana/minio,dvstate/minio,abperiasamy/minio,rushenn/minio,harshavardhana/minio,aead/minio,dvstate/minio,balamurugana/minio,krishnasrinivas/minio,aead/minio,jimjag/minio,NitishT/minio,aead/minio,krisis/minio,aead/minio,jimjag/minio