Use == not = for userId manualblocks lookup

Use the field match == operator, not the word match = operator when looking up menualblocks for a userId:

https://dev.folio.org/faqs/explain-cql/
Only the field match == operator has a database index:
https://github.com/folio-org/mod-feesfines/blame/v18.1.1/src/main/resources/templates/db_scripts/schema.json#L94-L104
Using the word match = operator results in a full table scan with bad performance when the the manualblocks table gets bigger.