All acts and parts of acts of the Legislature, whether general, special or local, in relation to correctional officers inconsistent with the provisions of this article shall be, and the same are, hereby repealed to the extent of such inconsistency.

Any civil service system for correctional officers in any county with a population of twenty-five thousand or more shall remain mandatory and shall be governed by the provisions of this article even if the population of such county shall at any time decrease below twenty-five thousand.