title: Invalid redirect URI on spotify auth
body: <p>I try to auth user through my app with spotify Web API but 
  I receive this error:</p>
  
  <pre><code>INVALID_CLIENT: Invalid redirect URI
  </code></pre>
  
  <p>URL:</p>
  
  <pre><code>GET https://accounts.spotify.com/authorize/?client_id=6ae90bf75bf748c8874a75d16682f0c5&amp;response_type=code&amp;redirect_uri=https%3A%2F%2Fexample.com%2Fcallback&amp;scope=user-read-private%20user-read-email
  </code></pre>
  
  <p>I cant see where is the problem... Can you help?</p>