[cq.cfg] Increase CQ percentage for linux_chromium_compile_dbg_ng from 0% to 5%

Bug: 731552
Change-Id: I4fc33ca2343d180d7920992ab4a7b5d3cadc7657
Reviewed-on: https://chromium-review.googlesource.com/899872Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Ryan Tseng <hinoka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534206}

infra/config/cq.cfg

@@ -98,7 +98,7 @@ verifiers {
       }
       builders {
         name: "linux_chromium_compile_dbg_ng"
-        equivalent_to { bucket: "luci.chromium.try" percentage: 0 }
+        equivalent_to { bucket: "luci.chromium.try" percentage: 5 }
       }
       builders {
         # The only purpose of this builder here is get data for migrating this