Update dynamic_supervisor.ex
Update dynamic_supervisor.ex

Closes #7291
joshprice/elixir,lexmag/elixir,pedrosnk/elixir,kimshrier/elixir,kimshrier/elixir,kelvinst/elixir,ggcampinho/elixir,gfvcastro/elixir,gfvcastro/elixir,elixir-lang/elixir,kelvinst/elixir,pedrosnk/elixir,ggcampinho/elixir,lexmag/elixir,michalmuskala/elixir