✨ (account) disable add user button if empty

src/components/AccountUserNew.vue

@@ -1,6 +1,12 @@
 <template>
   <div class="account-user-new">
-    <h3 v-if="showTitle" class="subtitle is-3">{{ $tc('account.friends', localeUsers.length, { count: localeUsers.length }) }}</h3>
+    <h3 v-if="showTitle" class="subtitle is-3">
+      {{
+        $tc('account.friends', localeUsers.length, {
+          count: localeUsers.length
+        })
+      }}
+    </h3>
     <user-new v-if="user && defaultUser" v-model="user" />
     <div v-for="(user, k) in localeUsers" :key="k">
       <user-new v-model="localeUsers[k]" @remove="() => remove(k)" />
@@ -17,7 +23,14 @@
         />
       </div>
       <div class="control">
-        <button type="button" class="button is-primary" @click.prevent="newUser">ajouter</button>
+        <button
+          type="button"
+          class="button is-primary"
+          :disabled="!newUserId"
+          @click.prevent="newUser"
+        >
+          ajouter
+        </button>
       </div>
     </div>
   </div>