old_contents: """
  Base config for tank.
  """
  
  from tiddlywebplugins.tank.wiki import (tank_uri, tank_tiddler_uri,
          tank_tiddler_resolver)
  
  config = {
      'extractors': ['http_basic', 'tiddlywebplugins.tank.extractor'],
      'auth_systems': ['tiddlywebplugins.tank.challenger'],
      'logged_in_redirect': '/dash',
      'wikitext.default_renderer': 'markdown',
      'wikitext.type_render_map' :{
          'text/x-markdown': 'tiddlywebplugins.markdown'
      },
      'markdown.wiki_link_base': '',
      'markdown.interlinker': tank_uri,
      'markdown.transclude_url': tank_tiddler_uri,
      'markdown.target_resolver': tank_tiddler_resolver,
      'markdown.extensions': (['markdown_checklist.extension'], {}),
  }
  
new_contents: """
  Base config for tank.
  """
  
  from tiddlywebplugins.tank.wiki import (tank_uri, tank_tiddler_uri,
          tank_tiddler_resolver)
  
  config = {
      'extractors': ['tiddlywebplugins.tank.extractor'],
      'auth_systems': ['tiddlywebplugins.tank.challenger'],
      'logged_in_redirect': '/dash',
      'wikitext.default_renderer': 'markdown',
      'wikitext.type_render_map' :{
          'text/x-markdown': 'tiddlywebplugins.markdown'
      },
      'markdown.wiki_link_base': '',
      'markdown.interlinker': tank_uri,
      'markdown.transclude_url': tank_tiddler_uri,
      'markdown.target_resolver': tank_tiddler_resolver,
      'markdown.extensions': (['markdown_checklist.extension'], {}),
  }
  
subject: Remove the http_base extractor