Remove blank tracking script.

Change-Id: Iffe8e4233a3f7c100d44502baffdc9515cbdf426

BUG=5905
TEST=Emerged metrics package

Review URL: http://codereview.chromium.org/3597004
diff --git a/metrics/omaha_tracker.sh b/metrics/omaha_tracker.sh
deleted file mode 100644
index e69de29..0000000
--- a/metrics/omaha_tracker.sh
+++ /dev/null