old_contents: try:
      from icrawl_plugin import IHostCrawler
      from plugins.applications.nginx import nginx_crawler
      from crawler_exceptions import CrawlError
  except ImportError:
      from crawler.icrawl_plugin import IHostCrawler
      from crawler.plugins.applications.nginx import nginx_crawler
      from crawler.crawler_exceptions import CrawlError
  import logging
  
  logger = logging.getLogger('crawlutils')
  
  
  class NginxHostCrawler(IHostCrawler):
      feature_type = 'application'
      feature_key = 'nginx'
      default_port = 80
  
      def get_feature(self):
          return self.feature_key
  
      def crawl(self):
          metrics = nginx_crawler.retrieve_metrics(
              host='localhost',
              port=self.default_port
          )
          return [(self.feature_key, metrics, self.feature_type)]
  
new_contents: try:
      from icrawl_plugin import IHostCrawler
      from plugins.applications.nginx import nginx_crawler
  except ImportError:
      from crawler.icrawl_plugin import IHostCrawler
      from crawler.plugins.applications.nginx import nginx_crawler
  import logging
  
  logger = logging.getLogger('crawlutils')
  
  
  class NginxHostCrawler(IHostCrawler):
      feature_type = 'application'
      feature_key = 'nginx'
      default_port = 80
  
      def get_feature(self):
          return self.feature_key
  
      def crawl(self):
          metrics = nginx_crawler.retrieve_metrics(
              host='localhost',
              port=self.default_port
          )
          return [(self.feature_key, metrics, self.feature_type)]
  
subject: fix F401 error