WiFi broadcast using Gstreamer is not possible right now.
This is feature that will be added in the near future.
You can download the 0.60 version in the link below.
http://community.emlid.com/t/softosd-a-software-hud-for-navio/
Download the latest version only 87Kb and replace the softOSD executable in the image.
Run it and will work.