Convert license for RLP data from cc-by-nc to cc-nc

As addressed in issue fraunhoferfokus/GovData#57 I have added a patch to
convert the license id cc-by-nc to cc-nc if applicable. The terms_of_use
fields are also updated accordingly.

Signed-off-by: Konrad Reiche <konrad.reiche@fokus.fraunhofer.de>