clean-processed-folder.py out of date for current filebeat registry behavior

[Seth Grover]

clean-processed-folder.py reads the filebeat registry file to ensure that it does not clean up files that filebeat still has in use.

However, the format of this file has changed at somepoint in the past and was no longer being read correctly.

These commits address the issue:

• mmguero-dev/Malcolm@708a301
• mmguero-dev/Malcolm@dd840ee
• mmguero-dev/Malcolm@e148cc6