fix theme and youtube icon
fix theme and youtube icon

PyBossa/pybossa-default-theme,AltClick/pybossa-amnesty-theme,PyBossa/mrallergen-theme,Scifabric/mrallergen-theme,AltClick/pybossa-amnesty-theme,PyBossa/mrallergen-theme,PyBossa/pybossa-default-theme,khadgarmage/pybossa-stardust-theme,Scifabric/mrallergen-theme,khadgarmage/pybossa-stardust-theme