[keymanweb.com] Not able to test with alpha version once I changed the Release Versions

[bharanidharanj]

Steps to Reproduce:

1. Open 'keyman.com' website in any browser.
2. Click Products / Pre-release Versions.
3. Click 'KeymanWeb latest alpha on keymanweb.com' link under KeymanWeb heading.
4. Verify that the Keyman alpha page appears with the mentioned web link "https://keymanweb.com/?tier=alpha&_ga=2.1867.." (alphapage)
5. Click "Return to version 15.0.274" link which appears at the top right corner of the page.
6. Verify that the Keyman 'stable' page opens. (stable)
7. Click "Try beta version 16.0.130" link at the top right corner of the page.
8. Verify that the Keyman 'beta' page opens. (beta)

Here, I noticed that I was not able to revert to 'alpha' page.

Expected: There should be a link 17.0 appears under the pre-release version.

..alpha page

..stable and beta page