src/app/shared/object-list: fix abstract in MyDSpace

Use dcterms.abstract in MyDSpace item list. It's not possible to
customize this in a theme so I have to do it in src/app.

src/app/shared/object-list/my-dspace-result-list-element/item-list-preview/item-list-preview.component.html

@@ -33,8 +33,8 @@ <h3 [innerHTML]="dsoTitle" [ngClass]="{'lead': true,'text-muted': !item.firstMet
           </span>
 
           <ds-truncatable-part [id]="item.id" [minLines]="1" class="item-list-abstract">
-            <span [ngClass]="{'text-muted': !item.firstMetadataValue('dc.description.abstract')}"
-              [innerHTML]="(item.firstMetadataValue('dc.description.abstract')) || ('mydspace.results.no-abstract' | translate)"></span>
+            <span [ngClass]="{'text-muted': !item.firstMetadataValue('dcterms.abstract')}"
+              [innerHTML]="(item.firstMetadataValue('dcterms.abstract')) || ('mydspace.results.no-abstract' | translate)"></span>
           </ds-truncatable-part>
 
         </div>