bugfix in CTiglCurveConnector
bugfix in CTiglCurveConnector

When checking if the "right neighbor guidecurvepart" has a dependency on the current guidecurvepart, it was never actually checked whether the "right neighbor guidecurvepart" exists.

fixes #446

DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl