Update Elixir Radar link

Author: José Valim

_includes/elixir-radar.html

@@ -11,7 +11,7 @@ <h3 class="widget-title">Elixir Radar Newsletter</h3>
       </div>
     </div>
     <div class="cta-button-container">
-      <a href="http://plataformatec.com.br/elixir-radar/weekly-newsletter?utm_campaign=elixir_lang_cta&utm_medium=cta&utm_source=elixir_lang_website" class="cta-button">
+      <a href="http://plataformatec.com.br/elixir-radar/?utm_campaign=elixir_lang_cta&utm_medium=cta&utm_source=elixir_lang_website" class="cta-button">
         Subscribe now
       </a>
     </div>