In/Outbound route for location undefined

[pschuler78]

On both forms when editing or creating new glider or motor flight and clear the location selection (may entering other location), the LocationService tries to load the InboundRoutes or OutboundRoutes by calling the API GET /api/v1/inoutboundpoints/location/undefined which result in bad request (error 400):

Steps to reproduce:

1. Create new glider flight or motor flight
2. If start or landing location already set, clear the start or landing location. The LocationService will try to load the routes, but the client sends undefined instead a locationId.
3. The server responses with error 400 bad request.