Database collector produces scrape error

It looks like there is a parsing error in the database collector that produces invalid metric output.

{
  "caller": "scrape.go:930",
  "component": "scrape manager",
  "err": "expected value after metric, got \"MNAME\"",
  "level": "warn",
  "msg": "append failed",
  "scrape_pool": "gitlab-monitor-database",
  "target": "http://10.220.16.101:9168/database",
  "ts": "2019-10-24T13:38:22.768Z"
}

The invalid line looks like this:

gitlab_database_stat_table_idx_tup_fetch{table_name="_backup_of_all_deleted_32718"}

It looks like somehow the value is printed as part of the metric name.