No voluntary transfer of any license, or of the rights thereunder granted, shall be made without the written approval of the commission; and any successor or assign of the rights of such licensee, whether by voluntary transfer, judicial sale, foreclosure sale, or otherwise, shall be subject to all the conditions of the license under which such rights are held by such licensee and also subject to all the provisions and conditions of this chapter to the same extent as though such successor or assign were the original licensee under this chapter: , That a mortgage or trust deed or judicial sales made thereunder or under tax sales shall not be deemed voluntary transfers within the meaning of this section.Provided