The age, citizenship, or residence of an individual, or his designation as other than an “employee” shall not be controlling in determining whether or not such individual is an employee within the meaning of the act, except that an individual not a citizen or resident of the United States shall not be deemed to be in the service of an employer when rendering service outside the United States to an employer who is required by the laws of the place where the service is performed to employ, in whole or in part, citizens or residents thereof and the laws in force therein on August 29, 1935, shall be deemed to have been in force at all times prior to that date.