[releng] Add workaround for vinagre

[Michael Catanzaro <mcatanzaro src gnome org>]

commit a4becc80338cac733e055fc371da5effb2904856
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Tue Jun 21 12:47:34 2016 -0500

    Add workaround for vinagre

 tools/smoketesting/sample-tarball.jhbuildrc |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/tools/smoketesting/sample-tarball.jhbuildrc b/tools/smoketesting/sample-tarball.jhbuildrc
index 7fca3fa..5c87daf 100644
--- a/tools/smoketesting/sample-tarball.jhbuildrc
+++ b/tools/smoketesting/sample-tarball.jhbuildrc
@@ -26,5 +26,10 @@ prefix = os.path.join(checkoutroot, 'install')
 # to speed up builds, try '--disable-static --disable-gtk-doc'
 autogenargs='--disable-static --disable-gtk-doc'
 
-# these are hard to build or interfere with system packages
+# https://bugzilla.gnome.org/show_bug.cgi?id=767917
+module_extra_env = {
+    'vinagre': {'CFLAGS': '-w' },
+}
+
+# these are hard to build
 skip = ['gitg']