Move state enums to the model code

src/addons.js

@@ -644,7 +644,7 @@ function importDatabase(addon, callback) {
                 if (!error) return iteratorCallback();
 
                 debug(`importDatabase: Error importing ${addon} of app ${app.id}. Marking as errored`, error);
-                appdb.update(app.id, { installationState: appdb.ISTATE_ERROR, error: { message: error.message } }, iteratorCallback);
+                appdb.update(app.id, { installationState: apps.ISTATE_ERROR, error: { message: error.message } }, iteratorCallback);
             });
         }, callback);
     });