Anyprovision in the rules of a registered society or branch which purports to deprive persons of membership of the society or branch or of any interest therein by reason of their service in any of the naval, military or air forces of the Crown . . . shall be of no effect, and no person shall be fined for failure to attend any meeting of the society or branch or otherwise to comply with the rules thereof if the failure was due to his or her service as mentioned in this subsection.