Local channels are never removed from LocalVMChannelAcceptor memory

[diegosalvi]

BUG REPORT

1. Please describe the issue you observed:

• What did you do?
  Just used client with local network enabled

• What did you expect to see?
  local channels should be removed from memory when closed

• What did you see instead?
  LocalVMChannelAcceptor keep a LocalVMChannel memory to force close them on acceptor close but such memory isn't cleaned in any other means. While using local connection such objects keep to be added to channels sets but they are never removed. Looking into a memory dump in production server I got 5GB retained from such list

Referenced channels are closed but still there