Hints for devhelp in main

Hints

• asv-url-not-secure
  org.gnome.Devhelp.appdata.xml:299 - http://www.gnome.org/friends/
  Consider using a secure (HTTPS) URL for this web link.
• asv-summary-has-dot-suffix
  org.gnome.Devhelp.appdata.xml:91 - Brskalnik dokumentacije API, namenjen razvijalcem programske opreme.
  The component summary should not end with a dot (`.`).