Bug#885505: bumping severity of pygtk bugs

[Jeremy Bicha]

Control: severity -1 serious
Control: tags -1 -buster


As part of the Python2 removal, it is our intent that pygtk will be removed from Testing before the release of Debian 11
"Bullseye". Therefore, I am bumping the severity of this bug to Serious to ensure that there is plenty of warning before
the Debian 11 release and to make the eventual removal of pygtk as smooth as possible.


On behalf of the Debian GNOME team,
Jeremy Bicha