Don't overwrite the jdbcTemplate if already set

[magno32]

Checking if the jdbcOperations/template has been set prior to getting the default from the beanFactory.

This is my fix at least. Refs #20

[jirutka]

+1, but code-style should be fixed:

-       if(jdbcOperations == null){
            obtainJdbcTemplate();
        }
+       if (jdbcOperations == null) {
            obtainJdbcTemplate();
        }