Don't works, can't start quickstart.py

Hi,
When i launch the quickstart.py script, I always seen the same error, for me or my friends testing InstaPy.

If anyone have an issues.. Thanks !

`Error, unable to determine correct filename for 64bit linux
Traceback (most recent call last):
File "quickstart.py", line 14, in
session = InstaPy(username=insta_username,
File "/usr/local/lib/python3.8/dist-packages/instapy/instapy.py", line 322, in __init__
self.browser, err_msg = set_selenium_local_session(
File "/usr/local/lib/python3.8/dist-packages/instapy/browser.py", line 131, in set_selenium_local_session
driver_path = geckodriver_path or get_geckodriver()
File "/usr/local/lib/python3.8/dist-packages/instapy/browser.py", line 38, in get_geckodriver
sym_path = gdd.download_and_install()[1]
File "/usr/local/lib/python3.8/dist-packages/webdriverdownloader/webdriverdownloader.py", line 174, in download_and_install
filename_with_path = self.download(version,
File "/usr/local/lib/python3.8/dist-packages/webdriverdownloader/webdriverdownloader.py", line 129, in download
download_url = self.get_download_url(version, os_name=os_name, bitness=bitness)
File "/usr/local/lib/python3.8/dist-packages/webdriverdownloader/webdriverdownloader.py", line 324, in get_download_url
raise RuntimeError(info_message)
RuntimeError: Error, unable to determine correct filename for 64bit linux`

从第 14 行的 quickstart.py 开始，跟踪 session 设置进入 instapy/browser.py，然后检查 webdriverdownloader 的 traceback 及其 get_download_url 路径。在 64 位 Linux 上重现该故障，并记录或验证修复方案，使 quickstart.py 能够在不出现所报告的 RuntimeError 的情况下启动。

由索引模型根据 Issue 内容生成。