Try reenabling builds for trusty.

rpki-pbuilder.sh

@@ -13,3 +13,10 @@ python rpki-pbuilder.py					\
     --apt-tree $HOME/repository.ng/			\
     --url-path /APTng					\
     --releases debian/jessie ubuntu/xenial
+
+python rpki-pbuilder.py					\
+    --svn-tree $HOME/source.ng/rpki.net/		\
+    --apt-tree $HOME/repository.ng/			\
+    --url-path /APTng					\
+    --backports python-django python-tornado		\
+    --releases ubuntu/trusty