No such index documents error after migration to 0.5.11

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**Gorse version**
(gorse-in-one:0.5.11)

**Describe the bug**
After migrating from 0.5.10 to 0.5.11, the recommend apis like '/api/feedback/non-personalized/popular, /api/feedback/:userId' returns this response: "No such index documents" error.

**To Reproduce**
Migrate from 0.5.10 to 0.5.11 and call recommends api. No change in postgres db.

**Expected behavior**
Api must return response without error

**Additional context**
Remigrating to 0.5.10 solves problem.

Thanks in advance

Start by reproducing the 0.5.10-to-0.5.11 migration without changing PostgreSQL, then call /api/feedback/non-personalized/popular and /api/feedback/:userId. Trace where the "No such index documents" response is produced; done means both recommend APIs return successfully after migration.

Written by the indexing model from the issue text.