[Browser] Show window background behind toolbar. Fixes JB#5875
[Browser] Show window background behind toolbar. Fixes JB#5875

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