OpenAIRE: fix unicode error in keywords field

* Fixes an unicode decoding error in the keywords field.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
OpenAIRE: fix issue in collection field

* Fixes an issue with the collections field that would raise an
  error when a user collection was no longer defined.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>