bug/172

Fixes the issue https://github.com/telefonicaid/fiware-connectors/issues/172

This PR should partially (or totally, still under study) fix the issue https://github.com/telefonicaid/fiware-connectors/issues/68 as well.
Hard to read this comment.
I would put a dot at the end of the first line and upper case 'Purge' on the second line.
Also, I would add a 'that: 
  Reached this point, it could be <i>that</i> the ...