communicate with the process so it can finish

camera1/handle-slide-syncer.py

@@ -23,6 +23,7 @@ def on_message(client, userdata, msg):
     print(msg.topic+" "+str(msg.payload))
     if msg.topic == "video/slidesyncer/sync":
         p = subprocess.Popen(["/home/curso/code/snowmix/camera1/slide_syncer.sh"])
+        print(p.communicate())
 
 
 client = mqtt.Client()