Fixed wrong proxy keyword (httpx)

[smorrin28]

Reverted PR #1149 since HTTPX now uses the keyword "proxy" instead of "proxies" (https://www.python-httpx.org/advanced/proxies/) to create any proxy values, this always throws an error when creating an AsyncTransport object if using the latest httpx version.

[Silverdoses]

Thanks for the PR. I ran into this issue today as well:

TypeError: Client.__init__() got an unexpected keyword argument 'proxies'

For additional context: the proxies keyword argument was deprecated in earlier versions of httpx and was removed entirely in version 0.28.0

This fix will solve issues when upgrading to latest version of httpx as dependency for other packages, like in my case.

[smorrin28]

As a temporary fix I just directly created the wsdl client and passed it as an argument:

httpx_client = ...
wsdl_client = httpx.Client(verify=True, proxy=None, timeout=300)
client = AsyncClient(self._base_url, transport=AsyncTransport(client=httpx_client, wsdl_client=wsdl_client))