Fix buildbot linux_chromium_dbg_ng reference in PRESUBMIT.

Build has migrated to LUCI.

R=danakj@chromium.org

Bug: 839600
Change-Id: I15fab6330a0215b4edf14318993ae4608d269dbe
Reviewed-on: https://chromium-review.googlesource.com/1044772Reviewed-by: danakj <danakj@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556191}

build/PRESUBMIT.py

@@ -21,6 +21,6 @@ def PostUploadHook(cl, change, output_api):
   return output_api.EnsureCQIncludeTrybotsAreAdded(
     cl,
     [
-      'master.tryserver.chromium.linux:linux_chromium_dbg_ng',
+      'luci.chromium.try:linux_chromium_dbg_ng',
     ],
     'Automatically added tests to run on CQ.')