remove #page-wrapper from theme antarctic

packages/app/src/components/Theme/ThemeAntarctic.module.scss

@@ -16,7 +16,6 @@
 
 .growi:not(.login-page) {
   // add background-image
-  #page-wrapper,
   .page-editor-preview-container {
     background-image: url('/images/themes/antarctic/bg.svg');
     background-attachment: fixed;