For the purpose of carrying out the provisions of this chapter, such city, town or municipality is hereby authorized to appropriate from the general fund not to exceed four-tenths of one percent of the total payroll of those included under the jurisdiction and scope of the chapter: PROVIDED, HOWEVER, That if the city council or other proper legislative body shall make an appropriation for the support of said commission equal to or more than the said continuing appropriation in any year, this section shall not be operative for said year but otherwise shall be in full force and effect.