Unable to use DB without username and password

Changed plexus.conf database definition to use mysql db that anyone can access (no user / no password) and got an error because it's trying to use a null username.

java.sql.SQLException: Access denied for user 'null'@'localhost' (using password: YES)

<resource>
<name>jdbc/continuum</name>
<type>javax.sql.DataSource</type>
<properties>
<property>
<name>driverClassName</name>
<value>com.mysql.jdbc.Driver</value>
</property>
<property>
<name>url</name>
<value>jdbc:mysql://localhost/test</value>
</property>
<property>
<name>username</name>
<value></value>
</property>
<property>
<name>password</name>
<value/>
</property>
</properties>
</resource>