Allow name property of user to be null

src/client/app/desktop/views/components/messaging-room-window.vue

@@ -1,6 +1,6 @@
 <template>
 <mk-window ref="window" width="500px" height="560px" :popout-url="popout" @closed="$destroy">
-	<span slot="header" :class="$style.header">%fa:comments%メッセージ: {{ user.name }}</span>
+	<span slot="header" :class="$style.header">%fa:comments%メッセージ: {{ name }}</span>
 	<mk-messaging-room :user="user" :class="$style.content"/>
 </mk-window>
 </template>
@@ -9,10 +9,14 @@
 import Vue from 'vue';
 import { url } from '../../../config';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
 	computed: {
+		name(): string {
+			return getUserName(this.user);
+		},
 		popout(): string {
 			return `${url}/i/messaging/${getAcct(this.user)}`;
 		}