docs; fix bad connection string example

Author: vkarpov15

lib/index.js

@@ -199,7 +199,7 @@ Mongoose.prototype.createConnection = function(uri, options) {
  *     mongoose.connect('mongodb://user:pass@localhost:port/database');
  *
  *     // replica sets
- *     var uri = 'mongodb://user:pass@localhost:port/database,mongodb://anotherhost:port,mongodb://yetanother:port';
+ *     var uri = 'mongodb://user:pass@localhost:port,anotherhost:port,yetanother:port/mydatabase';
  *     mongoose.connect(uri);
  *
  *     // with options