migrated ride height from a double value to a Distance

Change-Id: I15c18f90df384b0241f2ec5ef7e223ded96561d9

java/com.sap.sailing.server/src/com/sap/sailing/server/masterdata/DummyTrackedRace.java

@@ -658,7 +658,7 @@ public class DummyTrackedRace extends TrackedRaceWithWindEssentials {
     }
 
     @Override
-    public Double getAverageRideHeight(Competitor competitor, TimePoint timePoint) {
+    public Distance getAverageRideHeight(Competitor competitor, TimePoint timePoint) {
         return null;
     }
 }