FIX #621: FindDlg: buttons not shown (#717)

* FIX: FindDlg: buttons not shown cause by TabSheet height calculation error (ReCalc)

src/fFindDlg.lfm

@@ -3,7 +3,6 @@ object frmFindDlg: TfrmFindDlg
   Height = 469
   Top = 176
   Width = 875
-  AutoSize = True
   Caption = 'Find files'
   ClientHeight = 449
   ClientWidth = 875

src/fFindDlg.pas

@@ -2206,7 +2206,10 @@ end;
 { TfrmFindDlg.FormShow }
 procedure TfrmFindDlg.frmFindDlgShow(Sender: TObject);
 begin
-  AutoSize:=false;
+  {$IFDEF LCLCOCOA}
+  pgcSearch.DoAdjustClientRectChange();
+  {$ENDIF}
+
   pgcSearch.PageIndex := 0;
 
   if cmbFindFileMask.Visible then