Respect the obfuscated configuration parameter for in redis.

Currently this gem will send all data into new relic. I would like it to respect the `record_sql` configuration flag when it is set to `obfuscated`. This stops potentially sensitive data from getting logged in plain text to new relic. 

I decided to just use the already existing flag since I didn't quite think it would make sense to have an entire separate flag for just redis obfuscation. However, I'd be happy to change it to it's own configuration parameter if you think that's the way to go.