That type of error (SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol) can happen for a few reasons.
The most likely cause is that your DNS service provider has not yet tabled shopplugin.net in your DNS and the initial failure is being intercepted by your DNS provider to return a search-engine results page offering their own alternative “Did you mean?” counter-query results.
If you have the access on your server you might try running host shopplugin.net or nslookup shopplugin.net to verify it. Once shopplugin.net is properly available at your DNS provider, connecting to shopplugin.net for update checks, support key activation, etc. Hope that helps!
