libpng12 suspicious pgp key of a dead developer

[Francesco Yoshi Gobbo]

Hi, I was checking the key that needed importing for `libpng12`, and 
found out in Hacker News that Glenn Rander-Pehrson, the developer, died 
in 2018.. I find this suspicious enough to bring it to your attention.

Link hacker news: https://news.ycombinator.com/item?id=18297844
Link to the related page: 
https://sourceforge.net/p/png-mng/mailman/message/36447670