chore(combo): shorten syntax of filteringOptions

Author: Lipata

src/app/lists/combo/combo-features/combo-features.component.html

@@ -1,7 +1,7 @@
 
 <igx-combo #combo class="combo" [data]="lData" [displayKey]="'field'" [valueKey]="'field'"
     placeholder="Location(s)" searchPlaceholder="Search..." [allowCustomValues]="customValues"
-    (addition)="handleAddition($event)" [filteringOptions]="{ filterable: filterable }"
+    (addition)="handleAddition($event)" [filteringOptions]="{ filterable }"
     [showSearchCaseIcon]="showSearchCaseIcon" [itemsMaxHeight]="255" [disabled]="disabled">
 </igx-combo>