bugfix: make the drawer a singleton

src/plugins/sib-reactions.js

@@ -218,6 +218,12 @@ converse.plugins.add('sib-reactions', {
        */
       openEmojiPicker(ev) {
         ev.preventDefault();
+
+        // Avoid an error when opening a new picker
+        if (this.querySelector('emoji-picker')) {
+          return;
+        }
+
         const picker = new Picker();
 
         picker.addEventListener('emoji-click', e => {