there is a bug in VirtualMin, causing Edit databases privileges to be gone for normal users. In detail:
1) I upgraded my Virtualmin 2.611 to 3.190.gpl - this is the time a bug appeared
2) In 3.21 it still doesn't work
3) I have virtualmin domains and users, which have "MySQL" privileges - they are able to create new database.
4) After upgrading, their button "Edit databases" is gone, as if they don't have enough privileges for it - it works for root.
5) I didn't change anything.