Fix leaking streams (id from preload side)

[maidh91]

Issue

• flow: preload.messages() => gui.messages() => sidecar.messages()
• in preload,
  • sub = messages(patternFoo)
  • when calling sub.end/close, gui still subscribes patternFoo to sidecar
  • then if calling sub2 = messages(patternFoo) again
  • sub2.on(data) will receive 2 messages per event

=> sub2 should receive 1 message per event only, but because gui never unsub, so preload will receive duplicate messages

ref.

• [Buggy] Fix leaking streams (id from gui side) #587
• Fix leaking streams (id from preload side) #590