Revert "getDatabase: properly handle redis connection failures"

This reverts commit dd19d74149.

The code was already correct

lib/cartodb/carto_data.js

@@ -35,7 +35,7 @@ module.exports = function() {
         var redisKey = _.template(this.user_key, {username: username});
 
         this.retrieve(this.user_metadata_db, redisKey, 'database_name', function(err, dbname) {
-          if ( err ) { callback(err, null); return; }
+          if ( err ) callback(err, null);
           else if ( dbname === null ) {
             callback(new Error("missing " + username + "'s dbname in redis (try CARTODB/script/restore_redis)"), null);
           }