Fix up some comments in omf-common/envelope.rb.
Fix up some comments in omf-common/envelope.rb.

mytestbed/omf,mytestbed/omf,ardadouk/omf6,phelipealves/omf,nathansamson/OMF,maxott/omf6,nathansamson/OMF,phelipealves/omf,nathansamson/OMF,LABORA-UFG/omf,nathansamson/OMF,phelipealves/omf,nathansamson/OMF,nathansamson/OMF,mytestbed/omf,mytestbed/omf,LABORA-UFG/omf,ardadouk/omf6,phelipealves/omf,LABORA-UFG/omf,LABORA-UFG/omf