style: fix custom background filters media query

Author: Miodec

frontend/src/styles/media-queries-green.scss

@@ -59,6 +59,12 @@
   .pageSettings {
     .section {
       grid-template-columns: 1fr 1fr;
+
+      &[data-config-name="customBackgroundFilter"] {
+        .groups {
+          grid-template-columns: 1fr;
+        }
+      }
     }
     .settingsGroup.quickNav .links {
       display: grid;