Avoid DNS lookup if provided an IPv4 or IPv6

[JaggerJo]

Description

see issue #220

In short: Skip the DNS lookup if an IP was provided as Host.

Related Issue

#220
#216

Type of Change

• 📚 Examples / docs / tutorials / dependencies update
• 🔧 Bug fix (non-breaking change which fixes an issue)
• 🥂 Improvement (non-breaking change which improves an existing feature)
• 🚀 New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 🔐 Security fix

Checklist

• I've written tests (if applicable) for all new methods and classes that I created. (rake test)
• I've added documentation as necessary so users can easily use and understand this feature/fix.

[cla-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have the users @JaggerJo on file. In order for us to review and merge your code, please sign our Contributor License Agreement to get yourself added. You'll find the CLA and more information here: https://github.com/hivemq/hivemq-community/blob/master/CONTRIBUTING.adoc#contributor-license-agreement

[JaggerJo]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have the users @JaggerJo on file. In order for us to review and merge your code, please sign our Contributor License Agreement to get yourself added. You'll find the CLA and more information here: https://github.com/hivemq/hivemq-community/blob/master/CONTRIBUTING.adoc#contributor-license-agreement

✅ done

[pglombardo]

Thanks @JaggerJo! Let me work out the CLA bot issues and I'll aim to merge right afterwards.

[JaggerJo]

Thanks @JaggerJo! Let me work out the CLA bot issues and I'll aim to merge right afterwards.

Thanks @pglombardo !

Could you also take a look at:

• Client not Thread-Safe #219
• DNS lookup of provided IP prevents connection to broker running on localhost #220
• SubscribeAsync / UnsubscribeAsync does not check PacketIdentifier of response, just uses first received package #222

[sauroter]

@cla-bot check

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[pglombardo]

Thanks @JaggerJo! This will go out in the next release.

[pglombardo]

Released in https://github.com/hivemq/hivemq-mqtt-client-dotnet/releases/tag/v0.24.2