gtk4: Remove duplicate CSS rule

Author: jnsh

common/gtk-4.0/sass/_common.scss

@@ -500,11 +500,6 @@ button {
       padding-left: 5px;
       padding-right: 5px;
 
-      label {
-        padding-left: 2px;
-        padding-right: 2px;
-      }
-
       label {
         padding-left: 2px;
         padding-right: 2px;