http.whiteboard: Fix javadoc generation
http.whiteboard: Fix javadoc generation

Since this project does not conform to the expected project configuration
where all the project's package names start with the project name, we
must explicitly tell the javadoc task what packages to use.

The main javadoc builds (osgi.cmpn, osgi.enterprise, ...) work because
they include both the org.osgi.service.http project and the
org.osgi.service.http.whiteboard project on the sourcepath and the
org.osgi.service.http project's name ends up including the packages from
the org.osgi.service.http.whiteboard project.

osgi/osgi,osgi/osgi,osgi/osgi,osgi/osgi,osgi/osgi,osgi/osgi,osgi/osgi,osgi/osgi