Hints for gkrellm in main

Hints

• asv-developer-info-missing
  net.srcbox.gkrellm.GKrellM.metainfo.xml -
  This component contains no `developer` element with information about its author.
• screenshot-no-thumbnails
  No thumbnails have been generated for screenshot 'https://gkrellm.srcbox.net/gkrellm.png'.
  This could mean that the original provided screenshot is too small to generate thumbnails from.