fix for not found allow multi choice checkbox

Author: DariaBod

src/org/labkey/test/components/domain/DomainFieldRow.java

@@ -769,6 +769,8 @@ public DomainFieldRow clickRemoveOntologyConcept()
 
     public void setAllowMultipleSelections(Boolean allowMultipleSelections)
     {
+        WebDriverWrapper.waitFor(() -> elementCache().allowMultipleSelectionsCheckbox.isDisplayed(),
+                "Allow Multiple Selections checkbox did not become visible", 2000);
         elementCache().allowMultipleSelectionsCheckbox.set(allowMultipleSelections);
     }