fix .ico image handler error on windows startup (see #383)
fix .ico image handler error on windows startup (see #383)

SasView/sasview,lewisodriscoll/sasview,SasView/sasview,lewisodriscoll/sasview,SasView/sasview,SasView/sasview,SasView/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview,SasView/sasview,lewisodriscoll/sasview