change mqtt user for snapserver

utils/modules/snapserver.nix

@@ -32,7 +32,7 @@ in
           enabled = "yes"; // set this to yes to enable the mqtt-metadata-service
           hostname = "127.0.0.1"; // Hostname of the MQTT Broker
           port = 1883; // Port on the MQTT Broker to connect to
-          username = "shairport-mqtt"; //set this to a string to your username in order to enable username authentication
+          username = "espresense"; //set this to a string to your username in order to enable username authentication
           password = "insecure-password"; //set this to a string you your password in order to enable username & password authentication
           topic = "shairport"; //MQTT topic where this instance of shairport-sync should publish. If not set, the general.name value is used.
           //	publish_raw = "no"; //whether to publish all available metadata under the codes given in the 'metadata' docs.