Command to set a user's quota
When external quota commands are being used, the program set in this option will be called when Virtualmin wants to set the quotas for a Unix user. The parameters it is called with are :
  1. The Unix username
  2. The new soft quota in 1 kB blocks, or 0 for unlimited.
  3. The new hard quota in 1 kB blocks, or 0 for unlimited.