Download kernels from HTTPS, improve warning
Download kernels from HTTPS, improve warning

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Juanlu001/poliastro,anhiga/poliastro,poliastro/poliastro,Juanlu001/poliastro,anhiga/poliastro,newlawrence/poliastro,newlawrence/poliastro,anhiga/poliastro,Juanlu001/poliastro,newlawrence/poliastro