send_tick: set "first" field (#3271)
send_tick: set "first" field (#3271)

According to the docs, the tick event should return:
    {
     "first": false,
     "payload": "arbitrary string"
    }
i3/i3,Airblader/i3-original,i3/i3,Airblader/i3,i3/i3,Airblader/i3-original,stapelberg/i3,Airblader/i3,Airblader/i3-original,Airblader/i3-original,stapelberg/i3,i3/i3,Airblader/i3-original,stapelberg/i3,Airblader/i3,stapelberg/i3,Airblader/i3