Add a retry button on error page

If the error is WRONG_PASSWORD

templates/default/error.html.ep

@@ -9,6 +9,8 @@
       <a class="btn btn-primary btn-lg" role="button" href="<%= $self->url_for('/') %>"><%=l 'BACK_TO_MAIN_MENU' %></a>
       <% if ($err eq 'ERROR_NAME_CONFLICT'){ %>
       <a class="btn btn-default btn-lg" role="button" href="<%= $self->url_for('/') . $room %>"><%=l 'JOIN_THIS_ROOM' %></a>
+      <% } elsif ($err eq 'WRONG_PASSWORD'){ %>
+      <a class="btn btn-default btn-lg" role="button" href="<%= $self->url_for('/password') . '/' . $room %>"><%=l 'TRY_AGAIN' %></a>
       <% } %>
     </div>
   </div>