Clear master slackbuilds if already exist in dependencies
        or if added to install two or more times

def clear_masters(self):
        """Clear master slackbuilds if already exist in dependencies
        or if added to install two or more times
        """
        self.master_packages = Utils().remove_dbs(self.master_packages)
        for mas in self.master_packages:
            if mas in self.dependencies:
                self.master_packages.remove(mas)