[sailfish-browser] Enable special gstreamer plugin usage.
[sailfish-browser] Enable special gstreamer plugin usage.

alinelena/sailfish-browser,sailfishos/sailfish-browser,sailfishos/sailfish-browser,alinelena/sailfish-browser,sailfishos/sailfish-browser,rojkov/sailfish-browser,rojkov/sailfish-browser,alinelena/sailfish-browser,rojkov/sailfish-browser,sailfishos/sailfish-browser,sailfishos/sailfish-browser,alinelena/sailfish-browser