Minor scrollable list fixes (#9551)

* Make sure loading indicator has enough vertical space

* Respect reduce_motion setting for loading indicator

app/javascript/mastodon/features/account_gallery/index.js

@@ -103,7 +103,7 @@ class AccountGallery extends ImmutablePureComponent {
       );
     }
 
-    if (hasMore) {
+    if (hasMore && !(isLoading && medias.size === 0)) {
       loadOlder = <LoadMore visible={!isLoading} onClick={this.handleLoadOlder} />;
     }