Bug: TotalItems various int/str depending on the database

[subvillion]

If I use Mysql (mariadb) as ttrss back-end database ?items returns json value TotalItems as string
If I use Postgres as ttrss back-end database ?items returns json value TotalItems as int

postrges

{
  "api_version": 3,
  "auth": 1,
  "total_items": 33725,
  "items": [],
  "last_refreshed_on_time": "1565084077"
}

mysql

{
  "api_version": 3,
  "auth": 1,
  "total_items": "33725",
  "items": [],
  "last_refreshed_on_time": "1565084077"
}