Simba: Fix tab closing depending on the Sender.

Projects/Simba/simbaunit.pas

@@ -1637,8 +1637,13 @@ end;
 
 procedure TSimbaForm.ActionCloseTabExecute(Sender: TObject);
 begin
-  if(PageControl1.PageCount > 1)then
-    Self.DeleteTab(TTabSheet(Sender).TabIndex,false)
+  if(PageControl1.PageCount > 1) then
+  begin
+    if Sender is TTabSheet then
+      Self.DeleteTab(TTabSheet(Sender).TabIndex,false)
+    else
+      Self.DeleteTab(PageControl1.TabIndex,false)
+  end
   else
     Self.ClearScript;  //DeleteTab would take care of this already, but yeah, it's neater this way.
 end;