Qt: fixed spacing & margin properties of TBitBtn. issue #24531


git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41511 4005530d-fff6-0310-9dd1-cebe43e6787f
LCL: TCustomBitBtn call invalidate during design time if Spacing or Margin is changed


git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41512 4005530d-fff6-0310-9dd1-cebe43e6787f