fix: ensure Promise for syncOne

src/background/app.js

@@ -230,6 +230,10 @@ vmdb.initialized.then(function () {
           error: null,
         });
       }, function (data) {
+        if (data instanceof Error) {
+          console.error(data);
+          data = data.toString();
+        }
         finish({
           error: data,
         });

src/background/sync/base.js

@@ -500,7 +500,7 @@ function syncOne(service) {
 }
 function sync() {
   var service = getService();
-  return service && syncOne(service).then(autoSync);
+  return service && Promise.resolve(syncOne(service)).then(autoSync);
 }
 
 function checkAuthUrl(url) {