Extra line inserted when wrapping long lines

Here is some sample output:

  The data used in mapping may be obtained and used locally:
  
  
  ftp://ftp.uniprot.org/pub/databases/uniprot/current_release/knowledgebase/idm
  apping/
  
  Limitations: Map is fairly slow because the web service is slow.  It

And the input:

    # found at:
    #
    #   http://www.uniprot.org/mapping/
    #
    # The data used in mapping may be obtained and used locally:
    #
    #   ftp://ftp.uniprot.org/pub/databases/uniprot/current_release/knowledgebase/idmapping/
    #
    # Limitations:
    # Map is fairly slow because the web service is slow.