Issue #3310666: UpdaterForm throws an exception if you try to update to the next minor beta

src/Form/UpdaterForm.php

@@ -289,7 +289,7 @@ final class UpdaterForm extends FormBase {
           ->getReleaseUrl();
         $caption = $this->t('@caption (<a href=":url">Release notes</a>):', [
           '@caption' => $caption,
-          ':url:' => $release_notes_url,
+          ':url' => $release_notes_url,
         ]);
       }
       // If the next minor release is greater than the x.y.0 release, we should