Not able to filter get_contacts by list_ids

Calling this:
```
Brevo::ContactsApi.new.get_contacts(list_ids: [1,2,3])
```
Will generate a request to:
```
https://api.brevo.com/v3/contacts?listIds=1%2C2%2C3
```
Which seems to be an unsupported format by Brevo, it expects something like this:
```
https://api.brevo.com/v3/contacts?listIds=1&listIds=2&listIds=3
```