Update Smack to 4.0.5

The Smack version openhab currently uses contains security vulnerabilities. This PR updates Smack to the latest stable version.

For the record: While preparing the commit I found some issues with the current XMPP openhab action:
- It does not use DNS SRV records to resolve the XMPP server
- It does not allow TLS

If I find the time, I may address those issues with future commits.

And since Smack is on maven central, and becomes more and more modular (see the upcoming Smack 4.1 version), it would be great if I could add maven dependencies instead of binaries. Will this ever be supported by openhab? Maybe with openhab2?

i know you've just used the same pattern as used before but could you please remove System.out and use log.warn instead? It would be great if you could also enhance the error message (by at least using e.getErrorMessage())