examples: fix login-screen-page

Author: Pooya Parsa

examples/kitchen-sink/pages/login-screen-page.vue

@@ -1,5 +1,5 @@
 <template>
-  <f7-page>
+  <f7-page class="no-toolbar no-navbar no-swipeback">
     <div class="page-content login-screen-content">
       <div class="login-screen-title">Framework7</div>
       <form>