Fix nickname form width

src/plugins/muc-views/nickname-form.js

@@ -2,6 +2,9 @@ import tpl_muc_nickname_form from './templates/muc-nickname-form.js';
 import { CustomElement } from 'shared/components/element';
 import { _converse, api } from "@converse/headless/core";
 
+import './styles/nickname-form.scss';
+
+
 class MUCNicknameForm extends CustomElement {
 
     static get properties () {

src/plugins/muc-views/styles/nickname-form.scss

@@ -0,0 +1,3 @@
+converse-muc-nickname-form {
+    width: 100%;
+}