Add . and @ for domain selection labels

dashboard/src/components/MailinglistDialog.vue

@@ -18,6 +18,7 @@ const mailinglist = ref(null);
 const membersText = ref('');
 const membersOnly = ref(false);
 const active = ref(true);
+const domainList = ref([]);
 
 async function onSubmit() {
   busy.value = true;
@@ -66,6 +67,13 @@ defineExpose({
     membersOnly.value = m ? m.membersOnly : false;
     active.value = m ? m.active : true;
 
+    domainList.value = props.domains.map(d => {
+      return {
+        domain: d.domain,
+        label: '@' + d.domain,
+      };
+    });
+
     dialog.value.open();
   }
 });
@@ -94,8 +102,7 @@ defineExpose({
             <label for="nameInput">{{ $t('email.addMailinglistDialog.name') }}</label>
             <InputGroup>
               <TextInput id="nameInput" style="flex-grow: 1;" v-model="name"/>
-              <div class="input-group-label">@</div>
-              <SingleSelect v-model="domain" :options="domains" option-key="domain" option-label="domain" />
+              <SingleSelect v-model="domain" :options="domainList" option-key="domain" option-label="label" />
             </InputGroup>
             <div class="error-label" v-if="formError.name">{{ formError.name }}</div>
           </FormGroup>