These songs were made when the world was a different place, and people's ideas about it, and about their place in it, was very different from the way many of us see things now.  If you feel the need to change this frankly inoffensive song to suit your own, or your audience's, preconceptions about the way the world is, or should be, then that is your right.  What is not your right, of course, is to do that without saying that you have done so, saying why, and specifying the changes you have made.  I'm sure that you understand that.  A century and more ago, the notorious Dr. Bowdler re-wrote Shakespeare to make his naughty plays conform to a then-current model of correctness; Shakespeare's works survive, while Dr. Bowdler is remembered only as a vague synonym for ignorant, presumptuous censorship.  Food for thought, I guess.