Bug 1461784: Enable staging releases on try-comm-central; r=aki

Differential Revision: https://phabricator.services.mozilla.com/D1353

--HG--
extra : source : 8984e916c5d2fbf9ee878a0cad40bbd1baab4126
extra : histedit_source : f602fc2f8c6fbb631007557eb51ac1bc3fb42889

taskcluster/taskgraph/util/attributes.py

@@ -27,6 +27,7 @@ RELEASE_PROMOTION_PROJECTS = {
     'jamun',
     'maple',
     'try',
+    'try-comm-central',
 } | RELEASE_PROJECTS
 
 _OPTIONAL_ATTRIBUTES = (