Take weak reference to self in OnAckCallback

Author: nuclearace

Source/SocketIO/Ack/SocketAckEmitter.swift

@@ -136,8 +136,8 @@ public final class OnAckCallback : NSObject {
 
         guard seconds != 0 else { return }
 
-        socket.manager?.handleQueue.asyncAfter(deadline: DispatchTime.now() + seconds) {[weak socket] in
-            guard let socket = socket else { return }
+        socket.manager?.handleQueue.asyncAfter(deadline: DispatchTime.now() + seconds) {[weak socket, weak self] in
+            guard let socket = socket, let `self` = self else { return }
 
             socket.ackHandlers.timeoutAck(self.ackNumber)
         }