fix: no waiting state during screenshot

src/views/dashboard/components/Device.vue

@@ -187,7 +187,7 @@ export default {
       }
     },
     screenshot () {
-      publish(`${this.device.productId}/${this.device.id}/screenshot/ask`, JSON.stringify({ timestamp: Date.now() }))('screenshot').then(() => {
+      publish(`${this.device.productId}/${this.device.id}/screenshot/ask`, JSON.stringify({ timestamp: Date.now() })).then(() => {
         this.isShotting = true
         this.shot = null
       }, () => {