Bug #1329: Update advanced allocation row after applying default stretches function

With this patch the bug is even clearer. If you have a task of 3 days with 8h
per day, and you choose stretches function you will see that the task is
enlarged to 4 days with 6h per day.

FEA: ItEr76S04BugFixing

libreplan-webapp/src/main/java/org/libreplan/web/planner/allocation/streches/StrechesFunctionConfiguration.java

@@ -95,6 +95,7 @@ public abstract class StrechesFunctionConfiguration implements
     @Override
     public void applyOn(ResourceAllocation<?> resourceAllocation) {
         resourceAllocation.setAssignmentFunctionAndApplyIfNotFlat(StretchesFunction.create());
+        assignmentFunctionChanged();
     }
 
     @Override