Two small fixes in the NSW Matching.
The "no match found" Warning was found to be cluttering output files, after discussing with @nkoehler we decided to demote it to DEBUG level.
I also found that the matching did not take negative channel numbers into account. These will occur in case no matches are found, since each object in the Matching Algorithm is matched with channel -10 by default. This will not be overwritten with a proper channel number if there is no match found.