Setter of context in NetStream is not functional

[PatrickSCLin]

context = mixer.videoIO.context = nil, so this will cause context always be null.

open var context:CIContext? {
        get {
            return mixer.videoIO.context
        }
        set {
            mixer.videoIO.context = context
        }
    }

use newValue instead context in Setter.

open var context:CIContext? {
        get {
            return mixer.videoIO.context
        }
        set {
            mixer.videoIO.context = newValue
        }
    }

[shogo4405]

Certainly.