Fix read the docs canonical url

[nineteendo]

The current logic of grabbing the root from the canonical url is wrong:

You can easily see this if you remove this line from conf.py:

sphinxext-opengraph/docs/conf.py

Line 65 in 0cd67f5

ogp_site_url = 'https://sphinxext-opengraph.readthedocs.io/en/latest/'

Then you get something like this:

<meta property="og:url" content="https://sphinxext-opengraph.readthedocs.io/index.html">
<meta property="og:image" content="https://sphinxext-opengraph.readthedocs.io/_images/social_previews/summary_index_c6c9679d.png">

Documentation preview: https://sphinxext-opengraph--135.org.readthedocs.build/en/135

[m-aciek]

Why did you close @nineteendo? Wasn't it a right approach?

[nineteendo]

Because the code is correct:

>>> from urllib.parse import urljoin, urlparse, urlsplit, urlunsplit
>>> rtd_canonical_url = 'https://sphinxext-opengraph.readthedocs.io/en/latest/'
>>> parse_result = urlsplit(rtd_canonical_url)
>>> urlunsplit((parse_result.scheme, parse_result.netloc, parse_result.path, '', ''))
'https://sphinxext-opengraph.readthedocs.io/en/latest/'