mqttdpms: Enable automatic reconnect

Apparently, *paho-mqtt* does not enable automatic reconnect by default.

src/mqttdpms.rs

@@ -1,3 +1,5 @@
+use std::time::Duration;
+
 use futures::stream::StreamExt;
 use log::{debug, error, info, warn};
 use paho_mqtt as mqtt;
@@ -83,6 +85,10 @@ impl MqttDpms {
         let mut client = mqtt::AsyncClient::new(client_opts)?;
         let mut conn_opts = mqtt::ConnectOptionsBuilder::new();
         conn_opts.will_message(self.will_message());
+        conn_opts.automatic_reconnect(
+            Duration::from_millis(500),
+            Duration::from_secs(30),
+        );
         if self.config.mqtt.tls {
             let ssl_opts = mqtt::SslOptionsBuilder::new()
                 .trust_store(&self.config.mqtt.ca_file)?