ftp: Delete debug print.

* src/dctc/java/com/dataiku/dctc/file/FTPFile.java: Here.
copy: Correct spelling.

* src/dctc/java/com/dataiku/dctc/copy/CopyTaskRunnable.java: Here.
fixme: Add one.

* src/dctc/java/com/dataiku/dctc/copy/CopyTaskRunnable.java: Don't use
  logger. Should use the YellPolicy.
copy: Don't log.

* src/dctc/java/com/dataiku/dctc/copy/CopyTaskRunnable.java: Not
  needed, a summary of the error appends after the copy. And not the
  role of this class.