Prepared Statements in Java

Fix prepared statement code sample,
note correct code sample at https://github.com/couchbaselabs/devguide-examples/blob/master/java/src/main/java/com/couchbase/devguide/QueryPrepared.java
&
N1qlParams params = N1qlParams.build().adhoc(false);
N1qlQuery query = N1qlQuery.simple("select count from `mybucket`", params);