Fix compatibility with zwave-js-server version 3.0.0 and above.

[spudwebb]

The zwave-js-server version number no longer match the supported schema version, so I removed the checks on the zwave-js-server version. The schema version compatibility is now only checked on server side when the set_api_schema command is sent.

I also removed some compilation warnings.

[marcus-j-davies]

Thanks @spudwebb,

I have been meaning to switch this check over to the schemaVersion property reported in the output of the version event, as opposed to the server version, which was, until v3 the minor component being aligned with the schemaVersion

But I agree, not sure if its worth to keep this going.
Will get this merged soon (currently arranging flights for summer hols)