Set "Restrict Editing" password for specified VM config

@param valid PRL_HANDLE @param current password, NULL if VM is not restricted @param new password, NULL to remove restriction

@return PRL_RESULT .

PRL_RESULT PrlVmCfg_SetEditRestriction(
    PRL_HANDLE hVmCfg, 
    PRL_CONST_STR sOldPass, 
    PRL_CONST_STR sNewPass
);