fix: sample disconnect when all the messages are sent (#1176)

Co-authored-by: Carter Tinney <carter.tinney@microsoft.com>

Author: ks6088ts

samples/sync-samples/provision_symmetric_key.py

@@ -55,7 +55,7 @@
         device_client.send_message(msg)
         time.sleep(1)
 
-        # finally, disconnect
-        device_client.disconnect()
+    # finally, disconnect
+    device_client.disconnect()
 else:
     print("Can not send telemetry from the provisioned device")