No ordinance relating to railroads or railroad crossings with streets and other public ways, or relating to the conduct, duties, service or rates of public utilities shall be repealed by virtue of the passage of this code or by virtue of the preceding section, excepting as this code may contain provision for such matters, in which case this code shall be considered as amending such ordinance or ordinances in respect of such provisions only.
('72 Code, § 10.010)