When any school district has heretofore adopted a resolution providing for the assessment, levy and collection of a tax for general revenue school purposes, in accordance with the provisions of any Act of Assembly of the Commonwealth, and has given proper notice of its intention to adopt such resolution in the legal journal designated by rules of court for publication of legal notices and advertisements and in a newspaper of general circulation within the county in which the school district is located, in accordance with the provisions of the Act of Assembly authorizing the assessment, levy and collection of such tax, the resolution shall be valid and enforceable notwithstanding the fact that notice of intention to adopt it was not advertised in a newspaper of general circulation within the school district, if all other requirements of law concerning the adoption of the resolution and the proceedings relative thereto were complied with.