Removed OS X code targeted at versions prior to OS X 10.7.

At least 10.7 is required in 3.1 anyhow, so don't check for it needlessly.

See https://github.com/wxWidgets/wxWidgets/pull/55

src/osx/cocoa/textctrl.mm

@@ -1099,8 +1099,6 @@ wxWidgetImplType* wxWidgetImpl::CreateTextControl( wxTextCtrl* wxpeer,
             // we have to emulate this
             [v setBezeled:NO];
             [v setBordered:NO];
-            if ( UMAGetSystemVersion() < 0x1070 )
-                c->SetNeedsFocusRect( true );
         }
         else
         {