fix no headline

src/app/post/components/post-list/post-list.component.ts

@@ -66,8 +66,10 @@ export class PostListComponent implements OnInit {
       post.tags.some((tag) => tag && tag.slug === TagEnum.aLaUne)
     );
 
-    const headIndex = this.allPosts.findIndex((post) => post.id === headLineTag[0].id);
-    this.allPosts.splice(headIndex, 1);
+    if (headLineTag.length) {
+      const headIndex = this.allPosts.findIndex((post) => post.id === headLineTag[0].id);
+      this.allPosts.splice(headIndex, 1);
+    }
 
     this.allPosts = [...headLineTag, ..._.difference(this.allPosts, headLineTag)];
   }