[gnome-commander/ConvertWarningsToErrors] fix warning: unused variable

[Uwe Scholz <uwescholz src gnome org>]

commit 998c9b64e87235a756da6b7fae323f67fcf9c99c
Author: Andreas Henriksson <andreas fatal se>
Date:   Wed Apr 19 12:55:33 2017 +0000

    fix warning: unused variable
    
    gnome-cmd-tags.cc:72:13: error: 'no_support_for_libgsf_tags_string' defined but not used 
[-Werror=unused-variable]
     static char no_support_for_libgsf_tags_string[] = N_("<OLE2 and ODF tags not supported>");
                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
    Problem introduced in:
    
    commit d2b2782b76b6842f9684322e7fd45cf738bd9907
    "Properly report unsuported Doc.* tags"

 src/tags/gnome-cmd-tags.cc |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/tags/gnome-cmd-tags.cc b/src/tags/gnome-cmd-tags.cc
index ecbcc9f..193ed20 100644
--- a/src/tags/gnome-cmd-tags.cc
+++ b/src/tags/gnome-cmd-tags.cc
@@ -69,8 +69,10 @@ static char no_support_for_taglib_tags_string[] = N_("<ID3, APE, FLAC and Vorbis
 #endif
 
 #ifndef HAVE_GSF
+#ifndef HAVE_PDF
 static char no_support_for_libgsf_tags_string[] = N_("<OLE2 and ODF tags not supported>");
 #endif
+#endif
 
 #ifndef HAVE_PDF
 static char no_support_for_poppler_tags_string[] = N_("<PDF tags not supported>");