[librsvg] Fix links to code_of_conduct.md

[Federico Mena Quintero <federico src gnome org>]

commit eb13ddb7498f46aeffcf4008840b60d1f8f1db7e
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Nov 30 13:38:47 2017 -0600

    Fix links to code_of_conduct.md

 CONTRIBUTING.md |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 27847d3..3f7c594 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -84,7 +84,7 @@ If you need to add new tests (you should, for new features, or for
 things that we weren't testing!), or for additional information on how
 the test suite works, please see the file [`tests/README.md`][tests-readme].
 
-[coc]: code-of-conduct.md
+[coc]: code_of_conduct.md
 [gitlab]: https://gitlab.gnome.org/
 [bugs-browse]: https://bugzilla.gnome.org/page.cgi?id=browse.html&product=librsvg
 [mail]: mailto:federico gnome org