add SECURE_PROXY_SSL_HEADER in settings

lesspass/settings.py

@@ -175,3 +175,5 @@ DJOSER = {
     'PASSWORD_RESET_CONFIRM_URL': '#/password/reset/confirm/{uid}/{token}',
     'ACTIVATION_URL': '#/activate/{uid}/{token}'
 }
+
+SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')