Fix error due to duplicate line

SyntaxError: Identifier 'Highlight' has already been declared

qortal-ui-plugins/plugins/core/messaging/q-chat/q-chat.src.js

@@ -32,7 +32,6 @@ import Placeholder from '@tiptap/extension-placeholder'
 import Highlight from '@tiptap/extension-highlight'
 
 import { Editor, Extension } from '@tiptap/core'
-import Highlight from '@tiptap/extension-highlight'
 const parentEpml = new Epml({ type: 'WINDOW', source: window.parent })
 
 class Chat extends LitElement {
@@ -982,4 +981,4 @@ class Chat extends LitElement {
     }
 }
 
-window.customElements.define('q-chat', Chat)
+window.customElements.define('q-chat', Chat)