- Use data->multi and not data->multi_easy to refer to the active multi.
The easy handle's active multi is always data->multi.
This is a follow up to 757dfdf which changed curl so that an easy handle
used with the easy interface and then multi interface cannot have two
different multi handles associated with it at the same time
(data->multi_easy from the easy interface and data->multi from the multi
interface).
Closes https://github.com/curl/curl/pull/12665