Return if device is connected over console.

def is_console(self, users_text):
        """Return if device is connected over console."""
        if users_text is None:
            self.log("Console information not collected")
            return None

        for line in users_text.split('\n'):
            if '*' in line:
                match = re.search(self.vty_re, line)
                if match:
                    self.log("Detected connection to vty")
                    return False
                else:
                    match = re.search(self.console_re, line)
                    if match:
                        self.log("Detected connection to console")
                        return True

        self.log("Connection port unknown")
        return None