secured site has no login button

[jessopb]

Currently: securing the site to one channel has no login. one must go to /login manually.

Solution: Add a login button.

reproduce: Set up your siteConfig.json this way:

    "closedRegistration": true,
    "serveOnlyApproved": true,
    "publishOnlyApproved": true,
    "approvedChannels": [
      {
        "name": "@yourchannel",
        "longId": "yourchannelclaimid7113e7b7af68ebe1f924022",
        "shortId": "y"
      },
      {
        "name": "@thumbnails",
        "longId": "yourthumbnailchannelclaimidlsdkjfslfss",
        "shortId": "yo"
      }
    ],