bug: error creating poap censuses on `dev`

[lucasmenendez]

Describe the bug
Error raises when a census is created based on a strategy with a POAP:

Request example

curl  -X POST \
  'https://census3-dev.vocdoni.net/api/censuses' \
  --header 'Accept: */*' \
  --header 'Content-Type: application/json' \
  --data-raw '{
    "strategyId": 35,
    "anonymous": false
}'

Response (from the queue)

{
  "done": true,
  "error": {
    "error": "error evaluating strategy predicate: no snapshot found for eventID 159945",
    "code": 5026
  },
  "data": {},
  "progress": 0
}