In distraint or insolvency proceedings affecting the assets of an employer, claims for labor, salaries or wages not to exceed six hundred dollars to each claimant which have been earned within three months before the date of the distraint or commencement of the proceeding shall be paramount and superior to any claim preferred or presented by an agency of the state: PROVIDED, That this section shall not apply to any compensation payable to an employer or to an officer, director, or stockholder of a corporate employer.