In every case where the county commissioners and the county auditors have heretofore fixed or shall hereafter fix the compensation of the county treasurer, or where they have heretofore failed or shall hereafter fail to fix the compensation of any county treasurer, an appeal may be taken to the court of common pleas of the proper county by the commissioners or treasurer, in the same manner that appeals may now be taken from the reports of county auditors on settlement of the accounts of county treasurers in this Commonwealth: provided, that no appeal shall be taken in any case where the commissioners and auditors shall have fixed or shall have failed to fix such compensation prior to the approval of this act, unless the same shall be taken within thirty days after such approval; and on every such appeal the said court shall have power, in its discretion, to fix the compensation aforesaid finally.