Bug #903 项目管理界面，标签栏右键不应显示关闭项目

Forms/MainFrm.pas

@@ -453,7 +453,7 @@ end;
 procedure TMainForm.jtsProjectsMouseDown(Sender: TObject;
   Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
 begin
-  if Button = mbRight then
+  if (Button = mbRight) and (jtsProjects.TabIndex > 0) then
     dxpmTabSet.PopupFromCursorPos;
 end;