fixing implementation of /marks/{mark-id} end point: correct mark is now selected

Change-Id: I932eed30d237a3fe555ad3c4d26dfadd6fc4c7c5

java/com.sap.sailing.server.gateway/src/com/sap/sailing/server/gateway/jaxrs/api/LeaderboardsResource.java

@@ -640,8 +640,10 @@ public class LeaderboardsResource extends AbstractSailingServerResource {
         Mark mark = null;
         for (final RaceColumn raceColumn : leaderboard.getRaceColumns()) {
             for (final Mark availableMark : raceColumn.getAvailableMarks()) {
-                mark = availableMark;
-                break;
+                if (availableMark.getId().toString().equals(markId)) {
+                    mark = availableMark;
+                    break;
+                }
             }
         }
         if (mark == null) {