title: Unable acess dashboard after changing to https (error 400)
body: <p>I install Wordpress on google cloud platform(bitnami). 
  When I changed site/home URL to https from settings, homepage is work but dashboard can not access even I enter the right username and password.
  It show error 400. replying a posts is the same situation.</p>
  
  <p><img src="https://i.stack.imgur.com/cIvjy.png" alt="log screenshot"></p>
  
  <p>How do I fix it? Please help!</p>