optimize block audit scores db query

frontend/src/app/components/blocks-list/blocks-list.component.html

@@ -52,8 +52,7 @@
                   [ngStyle]="{'width': (100 - (auditScores[block.id] || 0)) + '%' }"></div>
                 <div class="progress-text">
                   <span *ngIf="auditScores[block.id] != null;">{{ auditScores[block.id] }}%</span>
-                  <span *ngIf="auditScores[block.id] === undefined" class="skeleton-loader"></span>
-                  <span *ngIf="auditScores[block.id] === null">~</span>
+                  <span *ngIf="auditScores[block.id] == null">~</span>
                 </div>
               </div>
             </a>