fixed on_close plot bug when it maximized
fixed on_close plot bug when it maximized

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