Desktop: Fixed error when exporting certain notes that contain plugin content

packages/lib/services/plugins/utils/getPluginNamespacedSettingKey.ts

@@ -0,0 +1,9 @@
+import getPluginSettingKeyPrefix from './getPluginSettingKeyPrefix';
+
+// Ensures that the plugin settings and sections are within their own namespace,
+// to prevent them from overwriting other plugin settings or the default
+// settings.
+
+export default (pluginId: string, key: string): string => {
+	return `${getPluginSettingKeyPrefix(pluginId)}${key}`;
+};