www-plugins/freshplayerplugin: depend media-sound/pulseaudio needs changing

`media-sound/pulseaudio` is now [masked in main tree](https://github.com/gentoo/gentoo/commit/4bb604086b130c3b14cc0cd261490e7e78bb56f7). The dependency [here](https://github.com/prototype99/didos/blob/10bf70a90449d268718f28d9af9c5c95033f1dc1/www-plugins/freshplayerplugin/freshplayerplugin-0.3.9-r6.ebuild#L40) should be changed into `media-libs/libpulse`.