title: keycloak redirect uri - app is downloaded instead of redirection to html
body: <p>I have a webapp that uses keycloak 4.8.3:Final version to log in using nginx as web server. The webapp was working fine for 2 year until last week we started facing an issue.
  Here is the link to the video <a href="https://youtu.be/jl2w3JsGqvk" rel="nofollow noreferrer">https://youtu.be/jl2w3JsGqvk</a></p>
  <p>We have setup keycloak redirect UI as shown in the video. On using the correct credentials for login instead of seeing the app, the browser downloads the app. I have no idea what is happening and no logs as well.</p>