fix(appdata): Fix iteration over overwriteObject in AppData class

ts/npmextra.classes.appdata.ts

@@ -178,7 +178,7 @@ export class AppData<T = any> {
       }
 
       if (this.options.overwriteObject) {
-        for (const key in Object.keys(this.options.overwriteObject)) {
+        for (const key of Object.keys(this.options.overwriteObject)) {
           console.log(`-> heads up: overwriting key ${key} from options.overwriteObject`);
           await this.kvStore.writeKey(key as keyof T, this.options.overwriteObject[key]);
         }