Updated shodan_search for new API

Updated to support new API, domain, and HTTPS.

Shodan has recently added new domains, new API, and everything
is now over HTTPS. Optional DB reporting has been update so it
can be used as input to RHOSTS for other modules.
the to_s i unnecessary here, unless you suspect tbl to ever be nil
also, if not blah.nil? can usually (almost always) be simplified to if blah.  The only time that's an issue is if you are specifically seeking nil vs false