RSSGuard 5 - How Use Space Bar to Open Article in External Browser

[88mm]

I just switched from rssguard-4.8.6 to rssguard-5.0.4. The one issue that I am having is that in rssguard-5 I can not seem to have the keyboard space bar open the current article in an external web browser. How do I do that? (It worked in rssguard-4.)
(I can double click the article title in the rssguard article list, but I was trying not to use the mouse.)