Fix #1063 in Lazarus 1.8

Fix a change of behaviour in Lazarus 1.8 not calling event OnChange when TabPage is changed programatically.

main.lfm

@@ -1156,6 +1156,7 @@ inherited MainForm: TMainForm
     AutoSize = True
     BorderSpacing.Bottom = 2
     ButtonHeight = 23
+    ButtonWidth = 23
     Caption = 'MainToolBar'
     Images = ImageList16
     Indent = 4
@@ -1176,7 +1177,6 @@ inherited MainForm: TMainForm
       Left = 225
       Height = 23
       Top = 2
-      Width = 5
       Caption = 'ToolButton2'
       Style = tbsDivider
     end
@@ -1205,15 +1205,13 @@ inherited MainForm: TMainForm
       Left = 174
       Height = 23
       Top = 2
-      Width = 5
       Caption = 'ToolButton6'
       Style = tbsDivider
     end
     object ToolButton7: TToolButton
       Left = 378
       Height = 23
       Top = 2
-      Width = 5
       Caption = 'ToolButton7'
       Style = tbsDivider
     end
@@ -1250,15 +1248,13 @@ inherited MainForm: TMainForm
       Left = 350
       Height = 23
       Top = 2
-      Width = 5
       Caption = 'sepAltSpeed'
       Style = tbsDivider
     end
     object sepQueue: TToolButton
       Left = 299
       Height = 23
       Top = 2
-      Width = 5
       Caption = 'sepQueue'
       Style = tbsDivider
     end

main.pas

@@ -29,7 +29,7 @@ interface
   {$else}
   lclintf,
   {$endif windows}
-  Graphics, Dialogs, ComCtrls, Menus, ActnList,
+  Graphics, Dialogs, ComCtrls, Menus, ActnList, LCLVersion,
   httpsend, StdCtrls, fpjson, jsonparser, ExtCtrls, rpc, syncobjs, variants, varlist, IpResolver,
   zipper, ResTranslator, VarGrid, StrUtils, LCLProc, Grids, BaseForm, utils, AddTorrent, Types, LazFileUtils, LazUTF8, StringToVK;
 
@@ -1692,6 +1692,9 @@ procedure TMainForm.FormCreate(Sender: TObject);
         if j <> 0 then StatusBar.Panels[i].Width:=j else
                   Ini.WriteInteger('StatusBarPanels',IntToStr(i),Statusbar.Panels[i].Width);
   end;
+ {$IF LCL_FULLVERSION >= 1080000}
+   PageInfo.Options := PageInfo.Options + [nboDoChangeOnSetIndex]
+ {$ENDIF}
 end;
 
 procedure TMainForm.FormDestroy(Sender: TObject);