Add stubs for wxNativeFontInfo::{Get,Set}Strikethrough() to wxGTK.

These functions are not implemented currently (just as their
{Get,Set}Underlined() counterparts) but should still be defined to allow the
code using wxNativeFontInfo to link.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70563 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/fontutil.cpp

@@ -133,6 +133,11 @@ bool wxNativeFontInfo::GetUnderlined() const
     return false;
 }
 
+bool wxNativeFontInfo::GetStrikethrough() const
+{
+    return false;
+}
+
 wxString wxNativeFontInfo::GetFaceName() const
 {
     // the Pango "family" is the wx "face name"
@@ -815,6 +820,11 @@ void wxNativeFontInfo::SetUnderlined(bool WXUNUSED(underlined))
     // can't do this under X
 }
 
+void wxNativeFontInfo::SetStrikethrough(bool WXUNUSED(strikethrough))
+{
+    // this is not supported by Pango fonts neither
+}
+
 bool wxNativeFontInfo::SetFaceName(const wxString& facename)
 {
     SetXFontComponent(wxXLFD_FAMILY, facename);