Fix incorrect account id parsing in authentication service

closes #66

Signed-off-by: Oguzcan Kirmemis <[email protected]>

lib/authService/authenticate.js

@@ -99,7 +99,7 @@ class Authenticate {
         // check whether accounts contains only one element and role is device
         var accounts = decoded_token.accounts;
         var did = decoded_token.device_id ? decoded_token.device_id : decoded_token.sub;
-        var accountId = accounts ? accounts[0].id : null;
+        var accountId = accounts && accounts.length > 0 ? accounts[0].id : null;
         let realm = getRealm(decoded_token);
         // put realm/device into the list of accepted topics
         await this.cache.setValue(realm + "/" + did, "acl", true);