Spurious warnings when passing an array of scales

[swt30]

julia> series = rand(100, 4);

julia> using Plots

julia> plot(series, layout=4, yscale=[:identity :log2 :ln :log10])
[Plots.jl] Initializing backend: pyplot
WARNING: scale Symbol[:identity :log2 :ln :log10] is unsupported with Plots.PyPlotBackend().  Choose from: Symbol[:identity,:ln,:log2,:log10]
WARNING: scale Symbol[:identity :log2 :ln :log10] is unsupported with Plots.PyPlotBackend().  Choose from: Symbol[:identity,:ln,:log2,:log10]
WARNING: scale Symbol[:identity :log2 :ln :log10] is unsupported with Plots.PyPlotBackend().  Choose from: Symbol[:identity,:ln,:log2,:log10]
WARNING: scale Symbol[:identity :log2 :ln :log10] is unsupported with Plots.PyPlotBackend().  Choose from: Symbol[:identity,:ln,:log2,:log10]

The final subplots look perfect, but these warnings are thrown anyway.

[BeastyBlacksmith]

This warning has reappeared