fix(logger): ignore appcontainer for core

Signed-off-by: Maxence Lange <maxence@artificial-owl.com>

lib/public/Log/functions.php

@@ -41,7 +41,7 @@ function logger(?string $appId = null): LoggerInterface {
  return new NullLogger();
  }
 
- if ($appId !== null) {
+ if ($appId !== null && $appId !== 'core') {
  try {
  $appContainer = OC::$server->getRegisteredAppContainer($appId);
  return $appContainer->get(LoggerInterface::class);