Allow to configure last_seen via MQTT. https://github.com/Koenkk/zigbee2mqtt/issues/1075

lib/extension/bridgeConfig.js

@@ -14,6 +14,7 @@ class BridgeConfig {
 
         // Bind functions
         this.permitJoin = this.permitJoin.bind(this);
+        this.lastSeen = this.lastSeen.bind(this);
         this.reset = this.reset.bind(this);
         this.logLevel = this.logLevel.bind(this);
         this.devices = this.devices.bind(this);
@@ -24,6 +25,7 @@ class BridgeConfig {
         // Set supported options
         this.supportedOptions = {
             'permit_join': this.permitJoin,
+            'last_seen': this.lastSeen,
             'reset': this.reset,
             'log_level': this.logLevel,
             'devices': this.devices,
@@ -47,6 +49,19 @@ class BridgeConfig {
         });
     }
 
+    lastSeen(topic, message) {
+        const allowed = ['disable', 'ISO_8601', 'epoch'];
+        message = message.toString();
+
+        if (!allowed.includes(message)) {
+            logger.error(`${message} is not an allowed value, possible: ${allowed}`);
+            return;
+        }
+
+        settings.set(['advanced', 'last_seen'], message);
+        logger.info(`Set last_seen to ${message}`);
+    }
+
     logLevel(topic, message) {
         const level = message.toString().toLowerCase();
         if (allowedLogLevels.includes(level)) {