Remove commented out line in wxOSX SetFocus()

No real changes, just remove a "TODO" comment as it seems it's safe to
do it after 5+ years (see f897d9ed1a which
added it).

src/osx/cocoa/window.mm

@@ -3045,8 +3045,6 @@ bool wxWidgetCocoaImpl::SetFocus()
     if ( [m_osxView isKindOfClass:[NSScrollView class] ] )
         targetView = [(NSScrollView*) m_osxView documentView];
 
-    // TODO remove if no issues arise: should not raise the window, only assign focus
-    //[[m_osxView window] makeKeyAndOrderFront:nil] ;
     [[m_osxView window] makeFirstResponder: targetView] ;
     return true;
 }