Fix OTA update start on check with / as base_topic prefix. #3010

lib/extension/otaUpdate.js

@@ -75,7 +75,7 @@ class OTAUpdate extends BaseExtension {
         }
         this.inProgress.add(device.device.ieeeAddr);
 
-        const type = topic.split('/')[3];
+        const type = topic.substring(settings.get().mqtt.base_topic.length).split('/')[3];
         if (type === 'check') {
             const message = `Checking if update available for '${device.name}'`;
             logger.info(message);