old_contents: from django.core.checks import Error
  from django.core.files.storage import FileSystemStorage, default_storage
  
  
  def storage_check(app_configs, **kwargs):
      if isinstance(default_storage, FileSystemStorage):
          return [
              Error(
                  'FileSystemStorage should not be used in a production environment.',
                  hint='Please verify your DEFAULT_FILE_STORAGE setting.',
                  id='s3file.E001',
              )
          ]
  
new_contents: from django.core.checks import Error
  from django.core.files.storage import FileSystemStorage, default_storage
  
  
  def storage_check(app_configs, **kwargs):
      if isinstance(default_storage, FileSystemStorage):
          return [
              Error(
                  'FileSystemStorage should not be used in a production environment.',
                  hint='Please verify your DEFAULT_FILE_STORAGE setting.',
                  id='s3file.E001',
              )
          ]
      return []
  
subject: Fix deployment check return value