remove media query for transition of grw-nav-slide-hr

src/client/styles/scss/_layout_growi.scss

@@ -28,10 +28,8 @@
       margin-right: 5px;
     }
 
-    @media screen and (min-width: 768px) {
-      #grw-nav-slide-hr {
-        transition: 0.3s ease-in-out;
-      }
+    #grw-nav-slide-hr {
+      transition: 0.3s ease-in-out;
     }
   }