Reference to AddJsonConverters() in xmldoc

[mausch]

https://github.com/elasticsearch/elasticsearch-net/blob/15fee30ff3a09e21f1aad364aa01d52f68bfba48/src/Nest/Domain/Connection/ConnectionSettings.cs#L142 says it's "faster then adding them using AddJsonConverters()" but there is no AddJsonConverters method in this project.

Apparently this was a change from a previous method doing something similar ( 0ac6db1 ) but since the original method isn't there any more I found that comment confusing. Please consider removing it.

[gmarz]

Fixed. Thanks for the report @mausch.