Query to /api/subscribers?list_id=... is malformed

[EliRibble]

From the docs the example query is:

curl -u 'username:password' 'http://localhost:9000/api/subscribers?list_id=1&list_id=2&page=1&per_page=100'

That is, list_id=1&list_id=2.

When using the go-listmonk client:

listService := client.NewGetSubscribersService()
listService.ListIds([]uint{4})
ctx := context.Background()
listService.Do(ctx)

This leads to a query like:

GET https://mailing-list.tealok.tech/api/subscribers?list_id%5B0%5D=%5B4%5D

Un-encoded that's:

https://mailing-list.tealok.tech/api/subscribers?list_id[0]=[4]

which is incorrect, and fails to filter by list_id.