Fix vertical offset for wxGTK wxStaticBox without label.

Don't use different size for the vertical border in wxStaticBox just because
it doesn't have any label, this just doesn't seem necessary and results in
different appearance for the static box with and without label.

Closes #14430.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71884 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/statbox.cpp

@@ -156,7 +156,7 @@ void wxStaticBox::GetBordersForSizer(int *borderTop, int *borderOther) const
 {
     const int BORDER = 5; // FIXME: hardcoded value
 
-    *borderTop = GetLabel().empty() ? 2*BORDER : GetCharHeight();
+    *borderTop = GetCharHeight();
     *borderOther = BORDER;
 }