changed login-box for box class in 500 page

public/500.html

@@ -18,7 +18,7 @@
       </div>
       <div class="row">
         <div class="large-5 large-centered columns">
-          <div class="login-box animated fadeIn">
+          <div class="box animated fadeIn">
             <h2 class="text-center">
               Estamos com problemas :(
             </h2>