Allow trusty for zaqar-specs

Zuul sets zaqar jobs to trusty - and all other specs job allow both
precise and trusty, do the same for zaqar-specs, so that the job can run
on trusty.

Change-Id: I073a9b2ea9d4d4b2b14e7378ac461d10cf0c4bdb

modules/openstack_project/files/jenkins_job_builder/config/projects.yaml

@@ -1334,7 +1334,7 @@
 
 - project:
     name: zaqar-specs
-    node: bare-precise
+    node: 'bare-precise || bare-trusty'
 
     jobs:
       - specs-jobs