Use outerHTML to render existing nickname form

src/converse-muc-views.js

@@ -1722,11 +1722,17 @@ converse.plugins.add('converse-muc-views', {
                     const container = this.el.querySelector('.muc-bottom-panel');
                     container.innerHTML = html;
                     u.addClass('muc-bottom-panel--nickname', container);
+                } else {
+                    const form = this.el.querySelector('.muc-nickname-form');
+                    if (form) {
+                        sizzle('.spinner', this.el).forEach(u.removeElement);
+                        form.outerHTML = html;
                     } else {
                         this.hideChatRoomContents();
                         const container = this.el.querySelector('.chatroom-body');
                         container.insertAdjacentHTML('beforeend', html);
                     }
+                }
                 u.safeSave(this.model.session, {'connection_status': converse.ROOMSTATUS.NICKNAME_REQUIRED});
             },