Gatherer: ensure pre-precreate of "object_changes" metric (PG storage)
Gatherer: ensure pre-precreate of "object_changes" metric (PG storage)

Used on the "Change event" dash. Caused an ugly warning if there were no
schema / config changes yet

cybertec-postgresql/pgwatch2,cybertec-postgresql/pgwatch2,cybertec-postgresql/pgwatch2,cybertec-postgresql/pgwatch2