Ensure the waypoint table doesn't get dirty

diff --git a/TomTom_Waypoints.lua b/TomTom_Waypoints.lua
index 47b0a74..27b5755 100644
--- a/TomTom_Waypoints.lua
+++ b/TomTom_Waypoints.lua
@@ -224,6 +224,7 @@ function TomTom:ClearWaypoint(uid)
         point.dlist = nil
         point.uid = nil
         table.insert(pool, point)
+        waypointMap[uid] = nil
     end
 end