Prevent unnecessary redraws of dependencies when opening a container.

Redraw was being done every time a task was rendered and one last time when all
the tasks are rendered. Doing only the last redraw is enough.

This change should improve performance when opening containers.

FEA: ItEr76S04BugFixing

ganttzk/src/main/java/org/zkoss/ganttz/TaskList.java

@@ -142,7 +142,6 @@ public class TaskList extends XulElement implements AfterCompose {
         taskComponent.afterCompose();
         if (relocate) {
             getGanttPanel().adjustZoomColumnsHeight();
-            getGanttPanel().getDependencyList().redrawDependencies();
         }
     }