Adjust users of subscriptionIcon

lib/REST/Miniflux/V1.php

@@ -814,12 +814,12 @@ class V1 extends \JKingWeb\Arsse\REST\AbstractHandler {
         } catch (ExceptionInput $e) {
             return new ErrorResponse("404", 404);
         }
-        if (!$icon['data']) {
+        if (!$icon || !$icon['data']) {
             return new ErrorResponse("404", 404);
         }
         return new Response([
             'id' => $icon['id'],
-            'data' => ($icon['type'] ?? "application/octet-stream").";base64,".base64_encode($icon['data']),
+            'data' => ($icon['type'] ?: "application/octet-stream").";base64,".base64_encode($icon['data']),
             'mime_type' => $icon['type'],
         ]);
     }

lib/REST/TinyTinyRSS/Icon.php

@@ -31,7 +31,7 @@ class Icon extends \JKingWeb\Arsse\REST\AbstractHandler {
             return new Response(404);
         }
         try {
-            $url = Arsse::$db->subscriptionIcon(Arsse::$user->id ?? null, (int) $match[1], false)['url'];
+            $url = Arsse::$db->subscriptionIcon(Arsse::$user->id ?? null, (int) $match[1], false)['url'] ?? null;
             if (!$url) {
                 return new Response(404);
             }