Add "dist:precise" to qpidd.

It is also marked NOPRIME, but some setups (devstack-gate) would
like to cache, but not install, all .debs to avoid false negative
tests due to network problems.  This way it can be cached only on
appropriate platforms.

Change-Id: Ia4216e9e8e6e7f55bf5fe9bc683fee97976a9b04
diff --git a/files/apts/nova b/files/apts/nova
index 3ebf57c..c16a708 100644
--- a/files/apts/nova
+++ b/files/apts/nova
@@ -19,7 +19,7 @@
 vlan
 curl
 rabbitmq-server # NOPRIME
-qpidd # NOPRIME
+qpidd # dist:precise NOPRIME
 socat # used by ajaxterm
 python-mox
 python-paste