[WIP] FIX logic in processOnChangeConditionForUpdateContext

[fgalan]

Comes from https://github.com/telefonicaid/fiware-orion/pull/4186/files#r955722788

[fgalan]

In the first commit of this PR (73da133), test pass OK.

In the second commit (c803c4a), we update with master, thus introducing the new tests added in PR #4204.

 ----------- Failing tests ------------------
  o  0000_subs_attrs_deletion/delete_attribute_in_condition.test
  o  0000_subs_attrs_deletion/delete_attribute_in_empty_condition.test

In sum: removing && !caP->skip in the code causes a change in the Orion behaviour.

[fgalan]

Looking into the failing tests:

Thus, the && !caP->skip is to preserve that attributes that doesn't have to be in the notification end there (as they has been deleted in the entity and the notification is supposed to show the current context information in the entity, not the deleted one).