Bug #1553: Fixed test due to change in behavior

As the code now is copied to the parent node, the test checking its value has to
be fixed.

FEA: ItEr77S04BugFixing

libreplan-webapp/src/test/java/org/libreplan/web/orders/OrderElementTreeModelTest.java

@@ -603,7 +603,7 @@ public class OrderElementTreeModelTest {
 
         // * infoComponent (code, name, description)
         assertThat(element.getName(), equalTo(name));
-        assertNull(element.getCode());
+        assertThat(element.getCode(), equalTo(code));
         assertThat(element.getDescription(), equalTo(description));
 
         // * initDate