corrects regression on dataset-table component

src/app/dataset-detail/components/dataset-table/dataset-table.component.html

@@ -6,10 +6,10 @@
     (keydown.enter)="sortBy(key)" [tabindex]="isDisplayed ? 0 : -1" [attr.role]="'columnheader'">
     <span class="sort-icons">
       <span class="icon">
-        <span class="fas fa-sort-up" [ngClass]="{'icon-red': sortValue === key && sortOrder === 'desc'}"></span >
+        <span class="fas fa-sort-up" [ngClass]="{'icon-red': sortValue.includes(key) && sortOrder === 'desc'}"></span>
       </span>
       <span class="icon">
-        <span class="fas fa-sort-down" [ngClass]="{'icon-red': sortValue === key && sortOrder === 'asc'}"></span >
+        <span class="fas fa-sort-down" [ngClass]="{'icon-red': sortValue.includes(key) && sortOrder === 'asc'}"></span>
       </span>
     </span>
     <span class="column-title" [ngClass]="{'active': sortValue === key}">{{ key }}</span>