fix(grid): remove unused style from summaries

Author: MPopov

projects/igniteui-angular/src/lib/core/styles/components/grid-summary/_grid-summary-component.scss

@@ -48,10 +48,6 @@
         @extend %grid-summary--fixed-width !optional;
     }
 
-    @include m(active) {
-        @extend %igx-grid-summary--active !optional;
-    }
-
     @include m(cosy) {
         @extend %igx-grid-summary !optional;
         @extend %igx-grid-summary--cosy !optional;