pulse: fix pa_card_info.profiles2 array to be NULL terminated

profiles2 is meant to be NULL terminated, according to its documentation
Fixes a crash in pavucontrol-qt
5 jobs for master in 1 minute and 58 seconds (queued for 1 second)
Status Job ID Name Coverage
  Container
passed #3149717
container_fedora

00:00:56

 
  Build
passed #3149718
build_on_fedora

00:00:41

 
  Pages
passed #3149719
pages

00:00:20

 
  Deploy
passed pages:deploy

00:00:23

failed pages:deploy

00:00:01