[Glitch] Minor scrollable list fixes

* Make sure loading indicator has enough vertical space
* Respect reduce_motion setting for loading indicator

Port 4ede51743e to glitch-soc

app/javascript/flavours/glitch/features/account_gallery/index.js

@@ -107,7 +107,7 @@ export default class AccountGallery extends ImmutablePureComponent {
       );
     }
 
-    if (hasMore) {
+    if (hasMore && !(isLoading && medias.size === 0)) {
       loadOlder = <LoadMore visible={!isLoading} onClick={this.handleLoadOlder} />;
     }