fix(LinkBubble): Display references in link bubble only if href is set

This prevents requests to `/resolve?reference=.../null` when a document
gets opened without a link being selected.

Contributes to nextcloud/collectives#1167

Signed-off-by: Jonas <[email protected]>

Author: mejo-

src/components/Link/LinkBubbleView.vue

@@ -69,7 +69,7 @@
 		</div>
 
 		<!-- link preview -->
-		<NcReferenceList v-else
+		<NcReferenceList v-else-if="href"
 			ref="referencelist"
 			:text="sanitizedHref"
 			:limit="1"