[server] Fixing create-metadata-table migration

Summary: This should not have been landed with this error. No excuses!

Test Plan:
Delete table, run SQL query in TablePlus.
Delete table, run script from server dir, as on Notion

Reviewers: ashoat

Reviewed By: ashoat

Subscribers: palys-swm, Adrian, atul, karol-bisztyga, benschac, boristopalov

Differential Revision: https://phabricator.ashoat.com/D2657