Set random proxy from proxylist.

def change_proxy(self, random=True):
        """
        Set random proxy from proxylist.
        """

        if self.proxylist.size():
            if random:
                proxy = self.proxylist.get_random_proxy()
            else:
                proxy = self.proxylist.get_next_proxy()
            self.setup(proxy=proxy.get_address(),
                       proxy_userpwd=proxy.get_userpwd(),
                       proxy_type=proxy.proxy_type)
        else:
            logger.debug('Proxy list is empty')