* avatar content-type fix

* team default empty values are empty array
* page caches only updated if there is actually a filter id set for the team

src/App/Handler/AvatarHandler.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Handler;
 
 use App\Service\AvatarService;
+use finfo;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\RequestHandlerInterface;
@@ -36,8 +37,10 @@ class AvatarHandler implements RequestHandlerInterface
         } catch (\UnexpectedValueException $e) {
             return new TextResponse("Avatar not found", 404);
         }
+        $finfo = new finfo(FILEINFO_MIME_TYPE);
+        $contentType = $finfo->buffer($avatarImageData);
         return (new TextResponse($avatarImageData, 200, [
-            'content-type' => 'image/png',
+            'content-type' => $contentType,
         ]))->withHeader('Expires', '0')
             ->withHeader('Cache-Control', 'must-revalidate');
     }