Change metadata original portal amendment

Similar to the commits before the metadata original portal amendment is
adjusted as well. If field is already set it is left, otherwise it will
be set to the default value 'http://datenregister.berlin.de'.

Signed-off-by: Konrad Reiche <konrad.reiche@fokus.fraunhofer.de>
Merge branch 'master' of github.com:fraunhoferfokus/ckanext-govdatade

Remove whitespace.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>

Conflicts:
	ckanext/govdatade/harvesters/ckanharvester.py