remove code

src/client/styles/scss/theme/_apply-colors-kibela.scss

@@ -34,11 +34,6 @@ body.kibela {
     }
   }
 
-  /* header*/
-  .background-t {
-    background-color: transparent;
-  }
-
   .search-input-group,
   .search-typeahead {
     .btn {

src/server/views/layout-kibela/widget/header.html

@@ -1,4 +1,4 @@
-<header id="page-header background-t">
+<header id="page-header">
   <div class="d-flex align-items-center">
     <div class="hidden-xs hidden-sm">
       <a class="logo" href="/">