Increase max concurrent flows to 1M.
Increase max concurrent flows to 1M.

Relates #51.

mavam/vast,pmos69/vast,pmos69/vast,pmos69/vast,mavam/vast,vast-io/vast,vast-io/vast,vast-io/vast,mavam/vast,vast-io/vast,mavam/vast,vast-io/vast,pmos69/vast