cbuildbot: Only pickup CL's in PCQ whitelisted repos if LCQ+1

BUG=chromium:909059
TEST=./run_tests

Change-Id: I44168013fee8a14936c9451ba226e0de03f36bff
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1593469
Commit-Queue: Jason Clinton <jclinton@chromium.org>
Tested-by: Jason Clinton <jclinton@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Evan Hernandez <evanhernandez@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
diff --git a/scripts/gerrit.py b/scripts/gerrit.py
index 7640419..919de26 100644
--- a/scripts/gerrit.py
+++ b/scripts/gerrit.py
@@ -42,6 +42,7 @@
     'CRVW': ['CR', 'Code Review    ',],
     'SUBM': ['S ', 'Submitted      ',],
     'VRIF': ['V ', 'Verified       ',],
+    'LCQ': ['L ', 'Legacy         ',],
 }
 
 # Order is important -- matches the web ui.  This also controls the short