Detection of esbonio_setup not working for Sphinx

[Daniel Woste]

In the function _load_sphinx_extensions is a small bug, which prevents esbonio from detecting esbonio_setup().

esbonio/lib/esbonio/esbonio/lsp/sphinx/__init__.py

Line 622 in 7ae7e8c

 if not hasattr(ext, "esbonio_setup"): 

This should be if not hasattr(mod, "esbonio_setup"):
So mod instead of ext.
Then everything works fine.

I will try to find some time later for a PR.

[Daniel Woste]

PR is there: #383
It's only changing 3 little characters.