[gnome-font-viewer] build: work around intltool bug with new automake

[Cosimo Cecchi <cosimoc src gnome org>]

commit 622b1876a5e1bfe5d882c9c18ad76810f768b33c
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Tue Mar 29 08:20:08 2016 -0700

    build: work around intltool bug with new automake
    
    See https://bugs.launchpad.net/intltool/+bug/1117944

 po/POTFILES.skip |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/po/POTFILES.skip b/po/POTFILES.skip
index a41978c..02e4ba6 100644
--- a/po/POTFILES.skip
+++ b/po/POTFILES.skip
@@ -1,3 +1,5 @@
 # List of source files that should *not* be translated.
 # Please keep this file sorted alphabetically.
 src/org.gnome.font-viewer.desktop.in
+# https://bugs.launchpad.net/intltool/+bug/1117944
+sub/src/org.gnome.font-viewer.desktop.in