Remove !default from property values

.themes/classic/sass/custom/_layout.scss

@@ -1,9 +1,9 @@
 // Here you can easily change your sites's layout.
 // To give it a try, uncomment some of the lines below, make changes, rebuild your blog, and see how it works.
 
-//$header-font-size: 1em !default;
-//$header-padding-top: 1.5em !default;
-//$header-padding-bottom: 1.5em !default;
+//$header-font-size: 1em;
+//$header-padding-top: 1.5em;
+//$header-padding-bottom: 1.5em;
 
 //$max-width: 1350px;
 //$indented-lists: true;