[Glitch] Fix jump when loading more media gallery items

Port 36d85f8521 to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

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

@@ -233,7 +233,7 @@ export const AccountGallery: React.FC<{
         alwaysPrepend
         append={accountId && <RemoteHint accountId={accountId} />}
         scrollKey='account_gallery'
-        showLoading={isLoading}
+        isLoading={isLoading}
         hasMore={!forceEmptyState && hasMore}
         onLoadMore={handleLoadMore}
         emptyMessage={emptyMessage}