net-irc/quassel[qt4,webkit] depends on dev-qt/qtwebkit:4 which is ancient and will never see any security updates.
Since there's a perfectly good Qt 5 available, I'd suggest just removing the qt4 USE flag completely.
(In reply to Michael Palimaka (kensington) from comment #0)
> Since there's a perfectly good Qt 5 available, I'd suggest just removing the
> qt4 USE flag completely.
Still font issues in Qt5/Plasma env as Qt 4 won't go away in the near future, I decided to keep qt4 build option.