anchor.diff:          'http404': {
               'level': 'WARNING',
               'class': 'logging.handlers.TimedRotatingFileHandler',
  -            'formatter': 'default',
  +            'formatter': 'thumbor',
               'filename': '<%= @log_dir %>/thumbor.404.log',
               'interval': 1,
               'when': 'D',
  
positive.code: from wikimedia_thumbor.logging.filter.context import ContextFilter
  from wikimedia_thumbor.logging.filter.http404 import Http404Filter
  
  
  THUMBOR_LOG_CONFIG = {
      'version': 1,
      'disable_existing_loggers': False,
      'formatters': {
          'default': {
              'format': '%(asctime)s %(port)s %(name)s:%(levelname)s %(message)s'
          }
      },
  
negative.code:         'errorstream': {
              'level': 'ERROR',
              'class': 'logging.StreamHandler',
              'formatter': 'thumbor',
              'filters': ['context', '404exclude']
          },
          'debugstream': {
              'level': 'DEBUG',
              'class': 'logging.StreamHandler',
              'formatter': 'thumbor',
              'filters': ['silentcontext']
          },
          'debug': {
              'level': 'DEBUG',
              'class': 'logging.handlers.TimedRotatingFileHandler',
              'formatter': 'thumbor',
              'filename': '<%= @log_dir %>/thumbor.debug.log',
              'interval': 1,
              'when': 'D',
  