fix: revert version

src/solid-xmpp-chat.js

 import './conversejs/converse.min.js';
 import './conversejs/emojis.js';
 import './plugins/converse-rai.js';
-import { Sib, store, StoreMixin } from 'https://cdn.skypack.dev/@startinblox/core@0.15';
+import { Sib, store, StoreMixin } from 'https://cdn.skypack.dev/@startinblox/core@0.14';
 import ComponentPath from './path.js';
 
 class Deferred {