fixing retain semantics

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@58947 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/mac/carbon/textctrl.cpp

@@ -3198,6 +3198,7 @@ void wxMacMLTEHIViewControl::SetBackground( const wxBrush &brush )
 
         CGColorRef color = CGColorCreate( wxMacGetGenericRGBColorSpace() , component );
         HITextViewSetBackgroundColor( m_textView , color );
+        CGColorRelease(color);
     }
     else
 #endif