Trigger desugar archiving on desugar_jdk_libs commits

Change-Id: I7d661fd2560cf6fba5e7d7201ada13c68855dd36
diff --git a/infra/config/global/luci-scheduler.cfg b/infra/config/global/luci-scheduler.cfg
index aa5d490..48d8058 100644
--- a/infra/config/global/luci-scheduler.cfg
+++ b/infra/config/global/luci-scheduler.cfg
@@ -45,10 +45,9 @@
 trigger {
   id: "desugar_library_trigger"
   acl_sets: "default"
-  # Apparently we need a gitilies task, this will never trigger.
   gitiles: {
-    repo: "https://r8.googlesource.com/r8"
-    refs: "regexp:refs/heads/NEVER_EXIST_BUT_MUST_HAVE.*"
+    repo: "https://github.googlesource.com/google/desugar_jdk_libs"
+    refs: "refs/heads/master"
   }
   triggers: "archive_lib_desugar"
 }