remove $light from default theme scss

src/client/styles/scss/theme/default.scss

@@ -17,7 +17,6 @@
 //
 html[light] {
   $primary: #112744;
-  $light: white;
 
   // Background colors
   $bgcolor-global: white;
@@ -62,7 +61,6 @@ html[light] {
 //
 html[dark] {
   $primary: #d65a31;
-  $light: white;
 
   $basecolor: #222831;