fix for oracle_login not checking connection status

Was using my resource script (oracle_login.rc) and noticed that it was taking a very long time and in investigating why discovered that oracle_login.rb doesn't check for any Oracle error messages when it rescues, so if for example the connection times out on the first brute force try, it will try N times (and have to wait through N timeouts), where N is the number of usernames/passwords you have it guessing.

This patch just has it check to see if Oracle specifically states the connection was timed out and if so, break so that the rest of the usernames/passwords are not tried, resulting in a speed up when the host is down.
Honestly this ```unless e``` inside the rescue hasn't a lot of sense to me. Is it working as is? 

I've the feeling then intended code was:

```ruby
    begin
      connect
      disconnect
    rescue ::OCIError => e
      break if e.to_s =~ /^ORA-12170:\s/
    else
      report_auth_info(
            :host  => "#{datastore['RHOST']}",
            :port  => "#{datastore['RPORT']}",
            :sname => 'oracle',
            :user  => "#{datastore['SID']}/#{datastore['DBUSER']}",
            :pass  => "#{datastore['DBPASS']}",
            :active => true
          )
     print_status("Found user/pass of: #{datastore['DBUSER']}/#{datastore['DBPASS']} on #{datastore['RHOST']} with sid #{datastore['SID']}")
    end
``` 

I haven't an oracle to test right now, do you mind to veryfy @ringt ? thanks!