Prevented creating jobrequisitionitems when not linked to a requisition

prs.desktop/Panels/Jobs/JobRequisitionItemGrid.cs

@@ -147,6 +147,11 @@ internal class JobRequisitionItemGrid : DynamicDataGrid<JobRequisitionItem>
         base.Reload(criteria, columns, ref sort, action);
     }
 
+    protected override bool CanCreateItems()
+    {
+        return Requisition.ID != Guid.Empty && base.CanCreateItems();
+    }
+
     protected override JobRequisitionItem CreateItem()
     {
         var result = base.CreateItem();